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LIBRARY 

OF THE 

UNIVERSITY OF CALIFORNIA. 

Class 



American Tool Making 

AND 

Interchangeable Manufacturing 



American Tool Making 

AND 

Interchangeable Manufacturing 



A Treatise upon the Designing, Constructing, Use, and Installation 
of Tools, Jigs, Fixtures, Devices, Special Appliances, Sheet- 
Metal Working Processes, Automatic Mechanisms, and 
Labor-Saving Contrivances ; together with Their Use 
in the Lathe, Milling Machine, Turret Lathe, 
Screw Machine, Boring Mill, Power Press, 
Drill, Sub- Press, Drop Hammer, etc., 
for the Working of Metals, the 
Production of Interchangeable 
Machine Parts and the 
Manufacture of Rep- 
etition Articles 
of Metal 



By 
JOSEPH V. WOODWORTH 

Author of "Dies, Their Construction and Use," "Hardening, Tempering, 
Annealing, and Forging of Steel," etc. 



ILLUSTRATED BY SIX HUNDRED ENGRAVINGS 

FROM ORIGINAL DRAWINGS BY 

THE AUTHOR 

^v 

OF THE 

UNIVERSfTY 



K jr 



1SIEW YORK 

NITJNN & COMPANY 
OK THE SCIENTIFIC 

361 

1906 



\\ 



COPYRIGHT, 1904, BY 

THE NORMAN W. HENLEY PUBLISHING COMPANY 

ALSO ENTERED AT 
STATIONERS' HALL COURT, LONDON. ENGLAND 



A II Rights Reserved 



COMPOSITION, ELECTROTYPING, AND PRESSWORK BY 

PUBLISHERS' PRINTING COMPANY 

NEW YORK, U. S. A. 



UNIVERSITY 

OF 
^ L If OH 




PREFACE. 



By this preface I offer to American tool-makers a treatise on 
their art and mine. My reasons for this venture are numer- 
ous, but chief among them is the fact that to every tool -maker, 
every machinist, every worker in metals, a knowledge of what 
can be attained in his art is to-day indispensable, and the attain- 
ment of that knowledge should be both easy and pleasant. 

This treatise is intended for the man at the head of the shop 
as well as the man at the lathe ; for the man who has neither the 
time nor the inclination to delve into ten or twenty volumes of 
more or less contradictory mechanical dissertation ; for the prac- 
tical man of the drafting-room, the tool-room, the machine-shop, 
and the forge. The work is dedicated to the work-bench of the 
mechanic and the office of the engineer. It is inscribed to all 
who are interested in the working of metals. If they shall gain 
knowledge by its perusal the author will be abundantly repaid. 

In the writing and illustrating of this work I have drawn 
upon the accumulated knowledge gained through many years of 
practical experience, and have embodied in it extracts from over 
three hundred original articles contributed by myself to the 
mechanical and the technical press. In arranging the text and 
the illustrations the following objects have been constantly kept 
in mind : 

I. To give accurate and concise descriptions of the funda- 
mental principles, methods, and processes by which the greatest 
accuracy and highest efficiency may be attained in the produc- 
tion of repetition parts of metal at the minimum of cost. 

II. To discuss and illustrate the great numbers of special 
tools, their construction and use, as fully as possible within the 
narrow limits of a single volume. 

III. To avoid all that is speculative, impracticable, and ob- 
solete in processes, methods, principles, design, and construction. 



*2 1 

& J J- 



8 PREFACE. 

IV. To preserve a clear and systematic arrangement of the 
numerous subjects, giving to each one its place according to its 
importance in the treatise. 

V. To secure a style and method of presentation in the work 
itself which shall please the busy man of metals, whether he 
labors in the shop, the draughting-room, the office, or the labor- 
atory. 

Thus my aim has been to increase the practical knowledge 
and the earning capacity of machinists, tool-makers, die-mak- 
ers, steel-workers, blacksmiths, model-makers, and foremen; 
to point out to superintendents where and how to secure the 
maximum of output from the minimum of cost and labor; to 
give general managers and proprietors of metal-working estab- 
lishments methods by which they may increase the output- and 
the income, and last, but not least to put into the hands of 
the earnest and intelligent apprentice a text-book of the art that 
has gained for the United States the industrial supremacy of 
the world. 

Whether these important ends have been attained, it is not 
for me but for the practical reader to decide. I have labored 
earnestly and assiduously to add to the world's stock of knowl- 
edge and to reach the ideal of what a work of this kind should 
be. 

I surrender the treatise, thus undertaken and completed, to 
the reader, apologizing for nothing contained in it or omitted, 
and asking of you only a considerate judgment and just recog- 
nition of the work. 

JOSEPH V. WOODWOKTH. 

NEW YORK, 
December, 1904. 



CONTENTS. 



CHAPTER I. 

THE INCEPTION, DEVELOPMENT, AND INSTALLATION OF THE MODERN SYS- 
TEM OF INTERCHANGEABLE MANUFACTURING. 

PAGES 

Eli Whitney Intel-changeability Interchangeable Manufacturing 
Modern Manufacturing of Intricate Machinery The American 
Toolmaker The Most Skilled Mechanic in the World, . . 19-27 

CHAPTER II. 
MACHINE TOOLS, DESIGNING, TOOL-MAKING, AND TOOL-ROOMS. 

Machine Tools The Designer The Great Principle of Reproduc- 
tion Functions of Jigs and Fixtures Templets Gauges Flat 
Jigs Box Jigs Work that should not be Jigged Jigs for 
Heavy Work Cheap Jigs Accurate Jigs Tool-rooms and 
their Equipment, 28-39 

CHAPTER III. 

FUNDAMENTAL PRINCIPLES, PROCESSES, AND PRACTICAL POINTS FOR JIG 
DESIGN AND CONSTRUCTION. 

Factors Involved The Locating and Holding Devices Simple Drill- 
ing-jigs Constructing Simple Jigs Processes of Accurate Jig- 
making The Button Method for Locating Drill Bushing-holes 
Patterns for Castings to be Jigged Locating and Finishing Drill 
Bushing-holes in Large Jigs Jig Work on the Plain Milling- 
machine Handling Large Jig Bodies Jig Feet, . . . 40-54 

CHAPTER IV. 

TYPES OF SIMPLE AND INEXPENSIVE DRILLING-JIGS; THEIR CONSTRUCTION 

AND USE. 

Two Types of very Simple Drilling-jigs A Simple Fourteen-hole 
Drilling-jig Jigs for a Bracket and Bearing Two Simple Drill- 
ing-jigs and their Use Two Drilling-jigs for the Speed-lathe 
A Drill-jig for Acetylene Gas-burners Drilling-jigs for Odd- 
shaped Castings Jig for Drilling Rough Castings in Pairs Jig 
for Drilling Cams, 55-80 



10 CONTENTS. 



CHAPTER V. 
INTRICATE AND POSITIVE DRILLING-JIGS. 

PAGES 

Jig for Drilling a Multiple Cam-body Drilling and Hub-facing Jig 
An Intricate Jig for Typewriter Bases Two Drilling-jigs for 
Small, Accurate Work Jig for Drilling an Aluminum Base 
Casting, 81-95 

CHAPTER VI. 

THE DESIGN AND CONSTRUCTION OF DRILLING-JIGS FOR HEAVY MACHINE 

PARTS, ETC. 

Constructing Large Drilling-jigs Jig for Drilling a Nailing-machine 
Cross-head Drilling-jig for Cast-iron Impression Rollers Drill- 
ing-jig for Dovetailed Slide Brackets Drilling- jig for Press- 
bolster Points to be Remembered, 96-105 

CHAPTER VII. 
DRILLING-JIGS OF NOVEL DESIGN AND CONSTRUCTION. 

Drilling Holes in a Spiral Line around a Cylinder Indexing Dial Jig 
for Drilling Small Cams Jigs with Indexing Plates Drilling 
Holes in a Spider Casting A Drilling and Tapping Jig A 
Novel Drill- jig, 106-119 

CHAPTER VIII. 

USE OF MILLING -MACHINES FOR MODERN TOOL-MAKING, INTERCHANGE- 
ABLE MANUFACTURING, AND JOBBING SHOP WORK. 

The Utility of Milling-machines Improvements in Construction 
Universal Milling-machines " Knee Type " of Milling-machines 
Milling-machines Compared with other Machine Tools The 
Milling-machine in the Tool -room Milling an Angle Plate Cir- 
cular Jig-making on the Miller Vertical Spindle Milling-ma- 
chines Doubt as to the Utility of Milling-machines, . . . 120-128 

CHAPTER IX. 
SIMPLE MILLING FIXTURES. 

Six Distinct Types of Simple Milling Fixtures Fixtures for Milling 
a Bearing in a Bracket Fixture for Use in Squaring the Ends 
of Duplicate Pieces Fixture for Use in Slotting and Dovetail- 
ing Small Pieces Fixture for Use in Gang Milling Fixture 
Used in Face-milling, 129-140 



CONTENTS. 11 

CHAPTER X. 

MILLING FIXTURES FOR ACCURATE WORK. 

PAGES 
Factors in the Successful Use of Accurate Milling Fixtures Fixture 

for the First Piece of Work Fixture for Use in Milling the Sec- 
ond Piece Description of Fixture for the Third Piece Index- 
ing Milling Fixture for Last Two Pieces, 141-151 

CHAPTER XI. 

MISCELLANEOUS MILLING FIXTURES AND SPECIAL TOOLS FOR SIMILAR 

WORK. 

A Milling Fixture for Drill-press Tables Jig for Milling Drill-press 
Spindle Heads Machining Drill Columns Chief Factor in Ma- 
chine Construction, . . . . . . . . 152-161 

CHAPTER XII. 

SPECIAL TOOLS, FIXTURES, AND DEVICES FOR MACHINING REPETITION 
PARTS IN THE TURRET-LATHE. 

The Use of Special Fixtures in the Turret-lathe Attachment for 
Forming Irregular Pieces from the Bur Box-tool for the Turret- 
head Two Special Chucks for the Turret-lathe Detail Sketches 
of Tools and Fixtures for Machining Pulleys Tools for Machin- 
ing a Special Casting A Multi-spindle Drilling and Tapping 
Attachment with Work Fixture, 162-189 

CHAPTER XIII. 

SPECIAL TOOLS, FIXTURES, AND DEVICES FOR MACHINING REPETITION 
PARTS IN THE SCREW MACHINE. 

Four Special Box Tools for the Screw Machine Screw -machine Fixt- 
ures and Tools for Making Speed Indicators Method for Fin- 
ishing Duplicate Work in the Screw Machine Fixtures for 
Forming Pieces of Irregular Outline, ...... 190-207 

CHAPTER XIV. 
THE CONSTRUCTION AND USE OF BORING FIXTURES AND SIMILAR TOOLS. 

The Drill Press and Boring Fixtures Boring and Facing Fixture for 
"Sextet" Castings Drill-press Boring-rig for Interchangeable 
Work Special Machine for Boring Brackets and Spindle-heads 
Boring Drill-press Tables Machining Round Tables Finish- 
ing Cup Centres Advantage in the Use of Special Tools, . . 208-223 



12 CONTENTS. 

CHAPTER XV. 
DESIGN MANUFACTURE AND USE OF MILLING -CUTTERS. 

PAGES 

Milling-cutters Classified The Design and Manufacture of Milling- 
cutters Standard Styles and Sizes of Cutters Undercut Teeth 
End Mills Side Clearance Inserted Tooth-cutters Limits 
of Inaccuracy Use and Abuse of Cutters Regrinding Quality 
of Steel to Use for Milling-cutters Selecting a Set of Cutters for 
a Milling-machine An Assortment of Milling-cutters Shell End 
Mills Spindle Surface Mills Gang Mills and Interlocking Cut- 
ters Making Cutters Most Vital Point in Milling-machine Prac- 
tice Speeds and Feeds for Milling-cutters Suggestions for Mill- 
ing 224-238 

CHAPTER XVI. 
THE HARDENING AND TEMPERING OF MILLING-CUTTERS. 

Hardening Heating Plunging Warping Lead Bath Degree of 
Hardness Injury in Hardening Test for Hardening Sand- 
blasting Heating and Hardening Large Cutters, . . . 239-243 

CHAPTER XVII. 

DRILLS AND DRILLING; FORMING TOOLS AND FACING TOOLS; COUNTER- 
BORES, BORING BARS AND REAMERS. 

Deep-hole Drilling The Twist Drill dumber of Cutting Edges De- 
sirable Advantages of the End-cut Drilling Holes by Pratt 
and Whitney Method Boring Hollow Spindles with a Hollow 
Drill Drill Notes Circular Forming Tools Plain Forming 
Tools Facing Counterboriug Counterbores Reaming Holes 
in the Turret-lathe Reaming Holes in Thin Discs Machine 
Reaming with "Floating" Reamer Reaming Taper Holes in 
Cast Iron Taper Reaming in the Screw-machine Reamers 
for Projectiles Taper Rose Reamers Centre Reamers Ream- 
ers for Babbitt Reaming Holes in Two Kinds of Metal Ma- 
chine Reaming of Brass Parts Square Reamers and Expansion 
Reamers "Home-made" Reamers Hand Reaming Increasing 
the Size of a Reamer when Worn, ...... 244-260 

CHAPTER XVIII. 
BROACHES AND BROACHING. 

The Operation of Broaching An Interesting Job of Broaching 
Some Points about Broaches and Broaching Broaching: Its Re- 
lation to Sheet-metal Work . 261-267 



CONTENTS. 13 

CHAPTER XIX. 
SHOP USE OF MICROMETER CALIPERS AND THE HEIGHT GAUGE. 

PAGES 

Micrometer Calipers Reading Micrometer Calipers to Ten-thou- 
sandths of an Inch Special Uses of Micrometer Calipers The 
Height-gauge and its Use, 268-278 

CHAPTER XX. 
MOULD CONSTRUCTION. 

Moulds Moulds for Crayon Pencils Moulds for Lead Balls Mak- 
ing Moulds for Telephone-receiver Pieces How an Accurate Set 
of Moulds was Machined in the Planer Moulds for Bicycle Han- 
dle Tips Moulds for " Poker Chips "Spherical Moulds, . . 279-299 

CHAPTER XXI. 

SPECIAL TOOLS, FIXTURES, DEVICES, ARRANGEMENTS, CONTRIVANCES, AND 
NOVEL METHODS FOR METAL WORKING. 

The Devising and Constructing of Special Tools Making Thin- 
threaded Brass Rings A Set of Special Tools for Machining a 
Cam Cutting a Coarse-Pitch Screw A Drill-press Job A 
" Step Jig "A Drilling Job in the Planer A Spring Winding 
Fixture A Soldering Face-plate Making Collet Spring Chucks 
A Flaking Stick Drilling Holes in a Helical Surface Milling 
in the Drill-Press A Simple Lathe Chuck Trimming Sheet 
Brass Blanks A Die-making Kink A Simple Slotting Fixture 
Keyseating in the Power-Press Hand Cut-off and Forming 
Tool Milling-Jig for the Speed Lathe Jigs and Fixtures for 
Adjustable Stops and Spindle Racks Milling Spindle Racks 
Jig for Drilling Small Thread Dies, 300-326 

CHAPTER XXII. 

SPECIAL TOOLS, FIXTURES, DEVICES, ARRANGEMENTS, CONTRIVANCES, AND 
NOVEL METHODS FOR METAL- WORKING Continued. 

A Machine for Twisting Corkscrews A Special Tool for Cutting 
Large Fibre Washers An Unusual and Special Job of Tool- 
making Special Engraving-Machine Special Cam-milling Ma- 
chine Chuck for Turning Eccentric Rings Chucking Fixture 
for Eccentric Cams Fixture for Chucking Gasoline-engine Cyl- 
inders Special Milling and Drilling Jigs A Set of Jigs for Mill- 
ing and Drilling Facing and Counterboring Large Spider 
Castings in the Drill-Press, . .... 327-354 



14 CONTENTS. 

CHAPTER XXIII. 
SPECIAL MACHINES FOR ACCURATE WORK ON DIES, AND THEIR USE. 

PAGES 

Progress Made in the Use of Power-Presses Hand-Finishing versus 
Machine-Finishing of Dies Die-sinking Attachment Machine 
for Filing Dies Die-shaper A Small Die-slotter A Die-tiling 
Machine, 355-364 

CHAPTER XXIV. 
THE ART OF SHEET-METAL WORKING IN DIES AND PRESSES. 

Use of Sheet Metal in Place of Other Materials Simplest Class of 
Press Tools" Gang " and " Follow " Dies Piercing and Perfo- 
rating Dies Processes of Drawn Work Depth which may be 
Drawn in Sheet Metal Annealing and Lubricating in Drawing 
The Drawing and Forming of Decorated Sheet-metal Articles 
"Finding " the Blanks from which to Draw Shells, . . 365-370 

CHAPTER XXV. 

THE MAKING AND USE OF PUNCHES AND DIES FOR SHEET-METAL 

WORKING. 

The Making and Use of Simple Dies Punching Brass Clock Gears 
Movable Stripping Devices Spring Strippers Punch and Die 
for End-finishing, Cutting-off, and Bending Sheet Metal from 
the Strip without Waste Two Dies for Metal Box -corner Fast- 
eners Piercing and Spreading Die for Box Straps An Im- 
proved Piercing Die Gang Die for Box -Lid Fastening Plates 
Large Drawing Dies for Circular Shells The Drawing of 
Deep Shells from Sheet Metal Hollow Cutters for Punching 
Leather, Cloth, or Paper, 371-30$ 

CHAPTER XXVI. 

THE MAKING AND USE OF PUNCHES AND DIES FOR SHEET-METAL 
WORKING . Continued. 

A Punching and Curling Job Dies for Sheet-metal Bag Clasps A 
Triple-action Die for Blanking, Drawing, and Embossing an 
Aluminum Shell in One Operation Blanking and Drawing an 
Aluminum Shell A Nice Job in Bending and Forming 
" Gang " Punch and Die for Producing Eyelets in One Operation 
Compound Dies for Parts of Telephone-transmitter Cases, . 399-431 



CONTENTS. 15 



CHAPTER XXVII. 

PROCESSES, PRESSES, DEVICES, AND ARRANGEMENTS FOR THE RAPID AND 
ECONOMICAL WORKING OP SHEET METALS. 

PAGES 

Press Work Perforating Flat and Cylindrical Sheet Metal Piercing 
and Blanking Small Armature Disks Keeping Sheets or Arti- 
cles Straight while Perforating Perforating Large Sheets of 
Metal in Special Designs Production of Perforated Metal by the 
Allis-Chalmers Company Horning and Seaming Processes 
Curling and Wiring Processes Manufacture of Armature Disks 
and Segments 432-460 

CHAPTER XXVIII. 

THE MANUFACTURE OF ACCURATE SHEET-METAL PARTS IN THE 
SUB-PRESS. 

The Sub-press Utility of the Sub-press not Generally Understood 
Principal Use of the Sub-press Cost versus Longevity of the 
Sub-press How to Construct a Sub-press Setting Up and 
Working a Sub-press Action of the Dies Feeding of the 
Metal 461-467 

CHAPTER XXIX. 

ENGRAVING, SINKING, CONSTRUCTING, AND USING DIES FOR MEDALS, 
JEWELRY, COINS, AND ART GOODS. 

Workman versus Artist Engraving a Hob for Sinking a Medal Die 
Chasing Thimble, Cane, Whip, and Umbrella Mountings 
Making Dies for Embossing Jewelry Modelling Intricate Die 
Patterns Gelatin Moulds Use of "Modeller's Wax "Dies for 
Forming Large Ornamental Articles Combination Dies for Em- 
bossed Work Making " Hobs " and Sinking Embossing Dies 
Bronze, Brass, and Copper Dies, . . 468-478 



CHAPTER XXX. 

THE MODERN ART OF SWAGING, SWAGING-MACHINES AND THE COLD- 
SWAGING PROCESS. 

The Hammer Swaging and Hammering The Cold-Swaging Proc- 
essRotary Swaging-Machines The Dayton Swaging-Machine 
Horizontal Swaging-Machines Some Effects of Work Accom- 
plished by Swaging, 479-491 



16 CONTENTS. 



CHAPTER XXXI. 

PROCESSES AND METHODS FOR THE WORKING OP ALUMINUM. 

PAGES 

Aluminum versus Other Metals Difficulties Encountered in Work- 
ingPure Metal versus Alloys Secrets in the Working of Alu- 
minumGrades and Alloys of Aluminum Working the Metal 
Lubricants to Use Cutting Dies for Aluminum Drawing 
Dies for Aluminum Drawing Aluminum Shells Bending and 
Forming Dies for Aluminum Spinning Aluminum Annealing 
Aluminum Polishing and Finishing Aluminum Burnishing 
the Metal Engraving and Chasing Aluminum Soldering Alu- 
minum Aluminum as an Abrasive, 492-500 

CHAPTER XXXII. 

HINTS, KINKS, WAYS, AND METHODS OF USE TO TOOL-MAKERS AND DIE- 
MAKERS. 

Notes on Circular Forming Tools A Kink for Drawn Work Brass- 
Working Tools and their Use Grinding Twist Drills for Cut- 
ting a Section of a Hole Truing and Turning Rubber Patent 
Tool-holders Hard-Soldering Speed of Pulleys and Gears 
Etching Steel Boring Long Cast-iron Tubes Tinning Castings 
A Handy Die and Tool -maker's Clamp Lubricant for Draw- 
ing Shells To Glue Leather to Iron Keeping Note-books, 501-511 

CHAPTER XXXIII. 
THE VALUE OF UP-TO-DATE FIXTURES AND MACHINE TOOLS. Conclusion. 

Lack of Knowledge of Machine Tools "Up-to-the-minute" Machine 
Tools Advantages Gained through the Use of Improved Tools 
- Ideal Twentieth-centurjr Manufacturing Depreciation in Ma- 
chine-shops Causes of Depreciation in Shops The Selection of 
Machines for Manufacturing Purposes Universal Equipment 
versus Working-range Equipment Cause of the Great Devel- 
opment in Machine Tools, ...... . 512-516 



American Tool Making 

AND 

Interchangeable Manufacturing 



AMERICAN TOOL-MAKING. 



CHAPTER I. 

The Inception, Development, and Installation of the 

Modern System of Interchangeable 

Manufacturing. 

ELI WHITNEY. 

THE inception of the modern system of interchangeable man- 
ufacturing according to the best authorities was in 1798 ; and 
the honor of being the first "interchangeable manufacturer" be- 
longed to Eli Whitney, the inventor of the cotton-gin, who, in 
January of that year, secured an order to furnish the United 
States Government with ten thousand muskets, four thousand to 
be delivered in one year and the balance in two years. We read 
that " Mr. Whitney went at the undertaking in a very thorough 
and systematic way. First, he developed a water-power, erected 
suitable and adequate buildings, considered ways and means for 
a larger and better product, designed machinery to effect it, and 
trained workmen to skill in the new employment. However, the 
difficulties which he encountered were greater than he had sup- 
posed, and it was eight years instead of two before the order of 
ten thousand arms was completed. Notwithstanding this delay, 
the progress of the enterprise and the character of the product as 
delivered was so satisfactory otherwise that Congress treated him 
with the greatest consideration. His shops at New Haven, Conn. , 
became the Mecca of government officials, manufacturers, travel- 
ling notables, and foreigners, and that which he could show was 
well worth a journey, for his innovations in the manufacture of 
arms were as epochal as his invention of the cotton-gin. " It was 
in the manufacture of those muskets that Whitney first conceived 
and put into successful operation "jigs" and "fixtures" for the 

19 



20 TOOL-MAKING AND 

duplicate production of parts to a limited degree of variation 
which would permit of their interchanging. Thus the modern 
manufacturing system was born the system that not only revo- 
lutionized the manufacture of arms, but became the basis upon 
which American manufacturers built their present-day reputa- 
tion of superiority in all other lines of manufactures. 

Having gone this far as the origin of the system has been 
traced and the inventor given due credit, as well as having paid 
tribute to his genius it will be well to proceed with the presen- 
tation of the meaning of "interchangeability" and the develop- 
ment, perfecting, and installation of the system for which it 
stands. 

INTERCHANGEABILITY. 

Interchangeability mechanically means to produce parts in 
duplication or repetition, or the production of a part or piece 
which will fit into the place provided for any other similar piece. 
As a rough sample of interchangeability we might take, for in- 
stance, the work of the brick-layer, the tile-setter, or the mosaic - 
worker, who when building a wall or blocking a panel take any 
brick, tile, or cube that lies nearest to their work, knowing that 
it will take up the same amount of space and fit into place the 
same as those laid before it. In metal, a rough sample of inter- 
changeability is met with when laying a line of water-pipe, the 
castings being dropped indiscriminately along the street, the con- 
tractor knowing full well that one end of each will fit into the 
recess of the end of the preceding one. 

From the laying of bricks, tiles, and water-pipe to the mak- 
ing of watches is quite a long step ; but as the modern watch, 
cheap and expensive, represents the other extreme of inter- 
changeability, developed to a degree almost incomprehensible to 
the ordinary mind, it is, a fitting illustration. In the manufac- 
ture of the watch hundreds of parts go to make it up. Take the 
screws the tiny little things that one can hardly see with the 
naked eye ; they are manufactured by the million, and so accu- 
rately that the last one will fit perfectly into the tapped hole 
provided for the first one. The gears, springs, brackets, pinions, 
pivots, bearings, and shafts are all interchangeable. 



INTERCHANGEABLE MANUFACTURING. 21 

In referring to interchangeability it must not be inferred that 
the system is only met with in the production of fine work ; on 
the contrary, the fact is that the system is easier of installation 
and of as frequent occurrence with rough work. 

In modern manufacturing the first object sought is to produce 
cheaply and therefore rapidly, and this object can only be at- 
tained by producing the parts or machines of the same kind in 
duplication. Some infer that these modern manufacturing 
methods have been adopted on account of the scarcity of skilled 
labor, when the fact is that it has been the great supply of highly 
skilled labor that has made the development, perfection, and in- 
stallation of the wonderful system of interchangeable manufac- 
turing possible. Thus where years ago the skill and ingenuity 
of the mechanic were monotonously and patiently utilized in the 
hand production of a number of parts of great accuracy to a cer- 
tain attainable degree of duplication, they are now directed to 
the devising and constructing of one part or tool, or a set of tools, 
which will produce other parts or tools in endless repetition. 
In modern machine manufacturing skill and ingenuity of an or- 
der higher than were ever thought possible to attain have been 
developed in the hands and brains of the American tool-maker. 
And this skill and ingenuity are concentrated upon the devising 
of means for the production of articles and parts within the 
slightest possible limits of variation, and in which their complete 
interchangeability will be guaranteed. 

The man in whose brain the modern manufacturing system 
was born was he that first took a piece of scrap-iron and drilled 
two holes in it, to guide a drill in making another piece with two 
holes in it the same distance apart as in the first piece. The 
men who now fill our drawing-rooms and tool-rooms and who de- 
vise and construct tools for the production of interchangeable 
metal parts are his descendants. They have made possible the 
manufacture of the breach -loading gun, the typewriter, the cheap 
sewing-machine, the cash-register, the machine-made watch, the 
automobile, as well as a thousand and one other mechanical arti- 
cles, machines, and devices, which form an integral part of our 
twentieth- century civilization. 



22 TOOL-MAKING AND 

INTEBCHANGEABLE MANUFACTUEING. 

The development of the modern system of manufacturing 
since the days of Eli Whitney has been simply wonderful, so that 
at the present time all machines for which there is a constant or 
a large demand are or should be manufactured and built through 
this system of interchangeability. It is in the perfecting of this 
system and in the designing and constructing of tools and appli- 
ances for the successful production of machinery that the best 
and brightest men in the mechanical field are employed. Take 
the universal milling-machine, the precision-lathe, the automatic 
screw -machine, and turret-lathe; all these machines are being 
manufactured to-day by a system which allows of their being 
constructed and shipped to any part of the world with their effi- 
ciency guaranteed. Moreover, any one of their innumerable 
parts can, when w r orn out or broken, be duplicated by sending 
to the works and securing the part needed. This'part can then 
be fastened in place of the other without as much as touching it 
with a file, w r hen it will perform its separate and distinct move- 
ments as positively and accurately as the part whose place it has 
taken. 

When one realizes that, in order for these machines to do the 
work expected from them, each and every part, from the most 
minute screw to the largest casting, must be finished to a degree 
of accuracy almost inconceivable to the lay mind, the fact that 
all the parts will interchange with those on another machine be- 
comes more surprising. Now if all the parts of a modern ma- 
chine tool must be finished so accurately, to what degree must 
the tools and appliances used to produce them be finished? And 
what of the men who have the skill and mental capacity neces- 
sary for the successful designing and constructing of such tools ! 

If it is considered that twenty years ago precision-machine 
tools of the present efficiency could not have been constructed, 
not even if the best mechanics available were employed on the 
work, the fact that they, as well as numberless others, are now, 
and have been, built by thousands, becomes more astonishing. 

The reason why such machinery could not have been per- 
fected and constructed to accomplish the results now attained by 



INTERCHANGEABLE MANUFACTURING. 23 

them was that there were not at that time tools and machines of 
the necessary precision and accuracy to build them, and it was 
only by inventing and developing the use of such tools that the 
manufacture of such intricate pieces of mechanism as the modern 
universal miller, precision-lathe, etc., was made possible. Nat- 
urally, in order to develop and construct these tools, the minds 
and hands of the mechanics had to be developed, until to-day the 
amount of brains, skill, and mental capacity involved in the de- 
signing and constructing of special machinery, dies, tools, and 
fixtures for the manufacturing of metal parts, articles, appli- 
ances, and machinery, is equal to if not greater than that 
called into use in any of the other arts and professions. 

This may seem a rather strong assertion to make, but it is 
made with the full knowledge of what it means. It may not be 
apparent to all, but to the man who has had the advantage of 
practical observation and experience in the manufacturing of 
machinery it is both right and just. It is well that the fact is 
becoming universally recognized that men of the highest and 
rarest attainments are engaged in the devising and developing of 
means for the rapid and economic production of machinery. 

MODEKN MANUFACTURING OF INTRICATE 
MACHINERY. 

As a practical illustration of what the modern system of 
manufacturing consists and how it is installed and carried, on, I 
will take up the various arts called into use and necessary to the 
successful constructing and placing on the market of a machine 
for which there is a large demand. 

After the developing and experimenting has reached a suc- 
cessful conclusion in a perfect working model, the first thing 
necessary is the designing and making of full sets of wood and 
metal patterns, to be used for casting the various parts which are 
to be cast. The man that does this must call into play a vast 
amount of ability and knowledge in order to accomplish this part 
of the work. He must allow of all parts being sufficiently 
strong, so that the castings resulting will withstand all strain to 
which they may be subjected when in use, and he must provide 
for giving them, as far as possible, a symmetrical and artistic 



24 TOOT^-MAKING AND 

appearance. He must also allow for shrinkage in the metal 
when cast and for a certain amount of surplus stock at all points 
which are to be machined and finished. 

After the pattern-maker has produced these patterns in exact 
duplication of the designs, they are sent to the foundry, where 
the moulder utilizes his skill and brains, and, with the patterns 
as models, a heap of sand and a few crude tools to work with, 
works out his moulds, from which a set of castings are produced. 
This set is first machined and finished by the use of the best 
means available, which calls into use all the capacity and skill of 
the machinist. After all parts have been finished and assem- 
bled, a finished machine is the result. Any defects in shape or 
strength in the patterns have now become apparent in the fin- 
ished castings and the parts. The patterns are then carefully 
gone over and these defects rectified, and another set cast from 
them. This set is also finished and machined, and then assem- 
bled in another machine. This latter machine is found to be a 
great improvement over the first, as all defects and inaccuracies 
have been rectified and each and every part has been machined 
as accurately as possible. 

The machine now goes to the tool-designer, who is called 
upon to scheme up and design complete sets of tools, dies, fixt- 
ures, and appliances for the machining of , all castings in repeti- 
tion and for the exact duplication of each and every other part, 
from the largest shaft and gear to the smallest pin and screw. 
To be capable of accomplishing all this the designer must be 
first of all a practical man, familiar with all mechanical princi- 
ples necessary to the successful construction of the tools, as well 
as be possessed of a theoretical knowledge of the properties of 
all metals. He must design the tools to be both positive and 
accurate, as well as strong and durable. He must also allow of 
their being constructed as simple as possible, consistent with ac- 
curate production and rapid handling when in operation. He 
must, lastly, he certain he is right in all measurements down to 
the smallest fraction of an inch. In fact, he must construct a 
perfect set of tools for the exact duplication of all the parts of 
the machine on paper. The designer must also provide for the 
tools being so constructed as to allow of being handled and oper- 



INTERCHANGEABLE MANUFACTURING. 25 

ated to their fullest capacity by men of the average skill aiid 
intelligence, with rapidity and without the possibility of error. 
By the time the designer has accomplished all this and gone over 
and verified all his designs, until he is sure of their accuracy and 
of their coinciding perfectly where necessary, he has finished his 
part of the work. 

The tool designs and the machine now go to the tool-maker ; 
he has the last, but not least, proposition to tackle. Where the 
pattern-maker had to produce his designs in wood, the draughts- 
man his on paper, and the moulder his in sand, the tool-maker 
has to create his in steel and iron, which can neither be whittled 
with a knife, nor the parts fastened together with glue, nor the 
mistakes and inaccuracies rubbed out with an eraser. Neither 
can the tool -maker shape his work in sand and locate the points 
with a trowel. He is the man on whom the accuracy, efficiency, 
and working qualities of the finished product depend. His skill, 
ingenuity, and powers of creation and production are taxed to 
their fullest extent indeed ; and, unless he is a man of brains, 
skill, and experience, all work of the designer, pattern-maker, 
and moulder will have been useless. First in the machining and 
finishing of the tools and the placing of all locating points, and 
then in the assembling of the parts, is his knowledge and skill 
called into play. As each tool, fixture, or device for the produc- 
tion of some special and distinct part is finished, it must be tried 
and proved ; and the piece machined in it must fit exactly in its 
proper position and coincide perfectly with all other points nec- 
essary in the other parts, so that the performance of its separate 
and distinct motion will be guaranteed. And thus on to the end 
of the list, until the full set of tools is complete, so that a perfect 
and complete machine can be constructed by their use, with the 
certainty that all parts machined in them will be found to inter- 
change perfectly, so that they may be selected haphazard in the 
assembling of a new machine or in the repairing of an old one. 
When all the foregoing has been accomplished, the preliminary 
work necessary to the successful manufacture and perfect opera- 
ting of the machines in any number desired, with the certainty 
that each and every one will be an exact duplicate of the others, 
from the smallest pin or screw to the largest casting, is an accom- 



26 TOOL-MAKING AND 

plished fact. We may now go ahead and manufacture by means 
of the interchangeable system, which allows of the construction 
of machinery at the minimum of cost and to the maximum of 
production ; and, what is more, allows of constructing machines 
in exact duplication of each other, which could not be accom- 
plished by any other means. 

THE AMERICAN TOOL-MAKEE THE MOST SKILLED 
MECHANIC IN THE WORLD. 

When all the skill, capacity, and brains utilized in the accom- 
plishment of the mechanical results outlined in the foregoing are 
considered, is it irrelevant to make the assertion that the genius 
and intelligence utilized in the inventing, developing, perfecting, 
and manufacture of machinery are second to none and above 
most? We think not ; and if any one who doubts the truth of it 
will stroll through a modern machine-shop, of the kind necessary 
to the production of intricate, labor-saving machinery, and notice 
the various operations through which the parts used in the con- 
struction of such machinery go, and the special tools, fixtures, 
appliances, arrangements, devices, and machinery used for their 
production, we think he will change his mind and will be grate- 
ful that America and Americans can boast of men who are capa- 
ble of such things; for it is to such as they, more than all others, 
that we owe our commercial and industrial supremacy of to-day. 
The great changes in the last century, which have contributed to 
the uplifting and betterment of the human race, are marked by 
the achievements of men whose whole lives and energies have 
been devoted to the perfection and production of things mechan- 
ical. This genius of invention which has conceived, developed, 
and made possible the manufacture of labor-saving machinery, 
has multiplied and improved the necessaries as well as the luxu- 
ries of life. 

We are known and acknowledged to-day as the greatest world 
power. What has made us so? It is to those who have devel- 
oped and perfected our modern manufacturing industries that we 
owe the most. It is because we can view with equanimity the 
strivings of other nations to outdo us ; because we can go out 
into the markets of the world and meet and overcome their com- 



INTERCHANGEABLE MANUFACTURING. 27 

petition, that we are what we are. Arid how has this come 
about? Simply through the great inventive ability and ingenu- 
ity of American engineers and mechanics. Thus has the pro- 
duction of all articles and necessaries of commerce been cheap- 
ened and multiplied. Go into the drawing, construction, or tool 
department of any of the large machine establishments and note 
the men employed therein. They will be found to bear favorable 
comparison with those engaged in any of the other arts or profes- 
sions. What is more, these men do not stand still, but keep 
increasing their knowledge, and thus step higher and higher to 
positions which their ambitions and capacities entitle them. 
From the ranks of such men come the best of our inventors of 
machinery, our superintendents and managers. 

Before closing this introductory chapter, I will say the indus- 
trial supremacy of the United States in the twentieth century has 
come about through the developing and perfecting of the modern 
system of interchangeable manufacturing, and will ever stand as 
a monument to the skill and ingenuity of the American me- 
chanic. 



CHAPTER II. 

Machine Tools, Designing, Tool-making, and Tool- 
Rooms. 

MACHINE TOOLS. 

IT has been well said that the foundation of the industrial 
structure of to-day rests on machine tools ; and with this state- 
ment, I believe, all who are familiar with the mechanical devel- 
opment of the last decade and have given any thought to indus- 
trial betterment will agree. It is a fact, that all must now 
concede, that without these machine tools, these wonderful fac- 
tors in modern civilization, we would be reduced to the state of 
primeval man and be forced to do by hard physical labor that 
which thousands of automatons now accomplish for us. It is with 
machine tools that all other machinery is produced ; the standard 
tools of the universal shop, the lathes, drills, planers, shapers, 
millers, boring-mills, and the numerous minor members of the 
great family, are all called upon to contribute their share to fur- 
ther economic modern manufacturing. 

Now, in view of the afore-mentioned facts, it must be obvi- 
ous to all that the nation which aims to lead in industrial mat- 
ters must be the one that possesses the most efficient and best de- 
veloped machine tools, as the possession of such is a criterion of 
the mechanical skill and ingenuity of the country's mechanics. 
Hence where the best machine tools are found there will also be 
found the best knowledge of how to operate them to the best ad- 
vantage. Thus we arrive at the conclusion that if good tools are 
to be made, a comprehensive and broad knowledge of how tools 
should be used and the amount of work they should do is abso- 
lutely essential. Of those who are possessed of this knowledge, it 
may be said that they are indeed ornaments to their profession, 
as they stand equipped to produce means which will lighten the 
load bequeathed by Mother Nature to both man and beast- 
means for doing the world's work economically and efficiently. 

28 



INTERCHANGEABLE MANUFACTURING. 29 

THE DESIGNEE. 

When considering machine tools we are at once confronted by 
the fact that the efficiency of any machine, device, arrangement, 
or tool used in manufacturing is determined solely by the quality 
and quantity of its output. To some extent this is modified by 
the skill of the workman using the machine or tool. However, 
machines ancj. tools should be designed and constructed so that 
the factor of skill in handling will be ineffective except in con- 
tributing to produce a better quality or a greater quantity of 
work than is demanded in the specifications. 

Now in order for the designer to be capable of designing a 
machine or a tool which will meet modern requirements, he must 
first be thoroughly practical and familiar with the details of the 
various lines of manufacture in which his creation is to be em- 
ployed. A theoretical knowledge of the properties of all materi- 
als, under all conditions, must also be possessed by the man who 
wishes to accomplish things in tool design, before he can hope to 
solve the innumerable problems which will confront him. When 
the vast field to be covered is considered, it is plain to all that 
the task that is set is no ordinary one and that his mental equip- 
ment must be very complete in order for him to succeed. It is 
well that the comparatively limited number of methods employed 
in the working of metals contribute somewhat to the lightening 
of his load. These methods may be enumerated as follows: 
forging, rolling, pressing, turning, drilling, tapping, planing, 
milling, grinding, punching, shearing, and sawing. This list 
comprises the most important methods ; the rest are minor and 
may be virtually classified under some one in the above-enumer- 
ated list. 

THE GEEAT PRINCIPLE OF EEPEODUCTIOK 

The designing and constructing of fixtures and special tools 
to be used in machine tools for modern manufacturing represent 
the highest application of the great principle of reproduction. 
It is this subject that we are about to take up, and it compre- 
hends not only the tools known as jigs and fixtures, but all spe- 
cial tools of various types which are in general use to-day for the 



OF THE 

UNIVERSITY 



30 TOOL-MAKING AND 

cheap and accurate production of parts in duplication and repe- 
tition, whether of metal or other material. The inception of the 
grand principle may be traced back almost to the beginning of 
time. 

Perhaps the earliest application of the principle of reproduc- 
tion was in the moulding of plastic materials which were after- 
wards baked. From the clays of the first use of moulds to the 
application of the principle in the art of printing was a long 
step, yet it was in that art that it next found use in printing 
from hand engravings and afterwards from removable type. Fol- 
lowing this, the principle was applied in the making of repro- 
ductions of paintings and lithographs, in the coining and stamp- 
ing of metals, and then in the casting of metals and numerous 
other materials. In fact, I might go on for pages and trace the 
application of the principle of reproduction down to to-day, and 
at length stop at a set of tools for the repetition production of a 
modern universal milling-machine or a precision-lathe. 

The most advanced application of the principle of reproduc- 
tion in which w r e are interested is to be found in the use of tem- 
plets, gauges, jigs, fixtures, and cradles, as those tools are chiefly 
used in working and cutting parts of metal, to a limited degree 
of variation, which have been previously roughly formed by the 
processes of rolling, drawing, forging, or casting. 

FUNCTIONS OF JIGS AND FIXTUKES. 

In jigs and fixtures their functions are often combined with 
those of machines in which they are used, such as a machine of 
special design fitted for operating on parts of the same size and 
shape, the work being located and the tools operated by devices 
self contained in the machine. This we find in a multiple spin- 
dle drill, which has been specially equipped for drilling all holes 
in a part of a machine or in a large plate, the drill-spindle cases 
being rigidly fixed in position in a certain relation to each other. 
In a machine of this type the position of the drill spindles repre- 
sent the jig, as it is only necessary to place the work on the table 
and the holes may be drilled in the same position as those in the 
preceding piece. 



INTERCHANGEABLE MANUFACTURING. 



31 



TEMPLETS. 

Templets are tools made of flat pieces of metal, usually 
sheet metal, which are used to lay upon surfaces and are lo- 
cated by the eye, fingers, or fixed flanges or pins, etc., so that 
certain edges of the templet, out- 
side or inside, may be used as a 
guide for scribing outlines of them 
on the surfaces of the work the 
outlines to serve as guides for drill- 
ing holes, cutting grooves below 
the general surface, or for forming 
the outer or inner edges of the part 
to the external or internal outlines 
of the templet. Thus a tool of this kind reproduces marked lines 
with accuracy to a degree dependable upon the care taken by the 
user. The working to those lines afterwards, however, is subject to 
variable error, as much depends upon the skill of the workman. 

As an illustration, let us say that we make a templet of con- 
siderable thickness and secure it firmly to the work, so as to allow 
of using'the locating edges for actual guides for the cutting tools 




FIG. 1. 






FIG. 2. 



FIG. 3. 



take Figs. 1 and 2, for instance. By doing this we get the 
simplest form of flat jig. When the outside edges of such a 
templet are used to locate finished edges in the work, the tool 
bceomes either a filing, milling, shaping, or planing jig, as the 
case may be. The most usual use of a flat jig, however, is to lo- 
cate cylindrical holes of various sizes and kinds to be drilled 
with drills or other similar tools, or to locate grooves, angles, or* 
keyways in parts in certain relative positions with other finishing 
points. Fig. 3 illustrates a die templet. 




32 TOOL-MAKISG ASD 

GAUGES. 

In gauges, their general function is to verify standard meas- 
urements between points and locations. While the use of such 
tools is well enough known to make a detailed description of them 
superfluous, a few remarks are essential. ID accurate work 

-limit " (Fig. 4) gauges are frequently 
used. One gauge represents the maxi- 
mum of allowable inaccuracy and the 
other the maximum of accuracy re- 
quired the work coming within these 
allowable limits. Thus we see that 

the purpose of gauges is not so much to locate the points of the 
various finished surfaces in a piece of work, as to inspect them 
after they are so located. 

FLAT JIGS. 

In regard to flat jigs it may lye said that the simplest form 
consists usually of a flat plate of iron, through which certain 
holes have been accurately located and carefully drilled ; the up- 
per and lower surfaces of the plate having first, of course, been 




FIG. 5. FIG. 6. 

machined true. Thus if a flat jig is in the form of a square, or 
of rectangular shape, and of considerable thickness, as shown in 
Fig. 5, or, in other words, of the same shape and size as the 
parts which are to be drilled, it may be clamped in position on a 
drill-press table and a pair of parallels used to set against two 
of its edges, the parallels being set at right angles to each other 
and damped when the drill has been set to enter one of the holes 
to the depth required, or all the way through, whichever may be 
the case. After this has been done the model or flat jig may be 



INTERCHANGEABLE MANUFACTURING. 33 

removed and the parts drilled iii exact duplication of it by setting 
them against the parallels and clamping them and then drilling. 
Then again the flat jig may be made to fit the top of the work 
and the holes drilled by guiding the drill through those in the jig. 
A type of flat jig most generally used is shown in Fig. 7. 
They are usually equipped with downward projecting lugs or 
pins, which are used to locate the jig on the work, thus obviating 
the necessity of depending on the hand or fingers of the operator 
for the locating. Very often devices, such as screws, clamps, or 
other fasteners, are contained in the jig (Fig. 8), being located 



/r 



o o o o o o o 
o o o o o o o 




FIG. 7. FIG. 8. 

upon one or more sides of the jig, the same serving to pull the 
jig in one or two directions against the work. Where the work 
varies in size or shape, such as in castings, the clamping is usu- 
ally central and made to operate in all directions, so as to com- 
pensate for the degree of variation in the castings. 

BOX-JIGS. 

In the further development of the reproducing principle, we 
come to the box -jig. This type of jig stands upon its own bottom 
when in use, the work being dropped into it and located by suit- 
able means against stops and down on bosses on the sides of the 
jig and on the inner surface of its bottom. A jig of this kind is 
usually equipped with a lid in which the bushings for guiding 
the drills are located. Very often the work is located and fast- 
ened within such jigs by merely dropping the lid down and fast- 
ening it. When all holes to be drilled in a box-jig are to be par- 
allel to each other, the jig always stands upon its bottom while 
in use ; but when holes are to be drilled at right angles, from the 
top and sides or from any of the six sides of the jig, it is neces- 
sary that all opposite sides from which drilling is to be done 

A. T.-3 



34 TOOL-MAKING AND' 

should be provided with surfaces for resting the jig ou the table. 
These resting surfaces or "bottoms" may be at any desired angle 
to each other, may be cast with the jig body and machined and 
squared, or be of steel and screwed or forced in. 

Box- jigs of the most common types are frequently used for 
drilling all holes in frames of small machines, standards, or other 
similar parts. The work is put into the jig and located by cer- 
tain surfaces which are most favorable for producing uniformity. 
After the work is located the jig is placed on the table of a gang 
drill and all holes finished as desired ; drilling, counter-boring, 
boring, or reaming, as may be desired, each spindle of the drill 
being equipped with the proper tools to accomplish the opera- 
tion required. Thus by the use of such jigs unskilled labor may 
be employed for drilling any number of accurately spaced holes 
in thousands of pieces, with the certainty that interchangeability 
will be assured. As the jig may be constructed so as to be easy 
to manipulate while sliding it from one spindle to another or 
turning it on its different sides, the physical exertion required of 
the operator is not great ; therefore the work is accomplished 
accurately with ease mentally and physically. 

Again, we will often find the box -jig in simpler form, the 
general shape being flat with a number of lugs or legs projecting 
downward. With a jig of this sort the lower surface of the lugs 
serve as legs, the work being clamped up against the lower sur- 
face of the jig body. Then, again, there is still another type, 
which might properly be called a "skeleton" jig, from the fact 
that it is merely a light skeleton frame in form. It is for very 
heavy work that these skeleton jigs are used, weight being a con- 
siderable factor, and in order for the operator to be able to han- 
dle the combined jig and work without undue exertion the jig 
must be made as light as possible. 

WOEK THAT SHOULD 2s T OT BE JIGGED JIGS FOE 
HEAVY WOEK. 

While most machine work can be "jigged" to advantage, 
there is some that it would be obviously impracticable to handle 
in this way; such as machine bases of large size, lathe beds, 
large press frames, etc. On the contrary, it is always well to 



INTERCHANGEABLE MANUFACTURING. 35 

continue doing all necessary work on such parts, such as turning, 
planing, and milling, by the ordinary methods; using templets 
and gauges for locating the finished surfaces, and then afterwards 
using small local jigs or templets for locating necessary holes 
from, some of the already finished surfaces. When jigs are used 
for such work they should be made for locating only one hole or 
for locating two or a number of them which are to be placed 
close together. When such jigs are made small enough, they 
may be handled with ease and located in succession on various 
parts of the work. 

While the saving of weight is very important in making large 
jigs in order to allow of their easy handling, it must not be car- 
ried too far. It is absolutely necessary in jigs for heavy work 
that lightness be combined with stiffness, and this can only be 
brought about through careful designing. Very often large jigs 
have been carefully made which, when fastened to the work, 
would bend or twist, thus throwing the holes and locating points 
out of place, the ca,use being inattention on the part of the de- 
signer to the factor of stiffness. 

For the frames of large jigs it will usually be found best to 
use cast iron, as with this metal the working parts will maintain 
their position without warping or bending; in fact, they will 
remain positive until a sufficient strain has been brought to bear 
on them to crack them. When bodies of such jigs are made of 
steel castings, forgings, or brass, they often become inaccurate, 
and these defects are not usually discovered until a large quantity 
of valuable work has been spoiled by their use. 

CHEAP JIGS. 

For small quantities of work cheap jigs are sometimes used. 
They are made by simply drilling the working holes through the 
body of the -cast iron or steel plate of which they are made. Of 
course, jigs of this construction are not very durable, as the 
drills wear the holes and the alignment is not maintained. 
Then, again, such jigs are made by fastening a hardened steel 
plate in which the proper working holes have been drilled to the 
frame of the jig. However, the use of hardened steel plates for 
the purpose designed is somewhat interdicted by the warping of 



36 



TOOL-MAKING AND 



the steel in hardening, thus destroying the alignment and displac- 
ing the holes in their relation to each other. 

ACCURATE JIGS. 

When large quantities of accurate work are to be done in 
jigs, the tools, of course, should be carefully made. In such jigs 
drill guiding holes should always be bushed with hardened, 




FIG. 9. 

lapped, and ground steel bushings, made to standard external 
diameters, so that they may be easily replaced when the inside 
has been worn by the revolving of the drills while working. 
Such bushings are usually forced tightly into reamed holes in the 
jig bodies. For producing accurate work in small quantities 
interchangeable bushings are used, a full set of them being kept 
on hand. These bushings may be used in any of the large jigs in 
the shop indiscriminately. 

TOOL-ROOMS AXD THEIR EQUIPMENT. 

Naturally, in a chapter devoted to the value of tools and the 
evolution and development of tool-making, one expects to find 



INTERCHANGEABLE MANUFACTURING. 



37 



something on tool -rooms ; at all events, a few remarks on the 
subject will be timely. 

Tool-rooms are of two classes those in which tools and fixt- 
ures are made and those in which they are kept. In those of 
the first class the most important item is the lathe. An approved 
type of a modern tool-maker's lathe is shown in Figs. 9 and 10, 



L2JL 




FIG. 10. 

the general features of which are apparent. It is a ten-inch, 
tool-maker's lathe, and its design and construction represent the 
attainment of perfect and complete convenience. It is one of the 
most complete precision-lathes ever produced for the tool-maker 
or model-maker. Now, of all machine tools, for either tool -mak- 
ing or manufacturing, the lathe is king. If a machine-shop or a 
tool -room is to have only one tool in it, it is obvious to all that 
the tool should be a lathe, and it should be a good lathe. With 
a good lathe and a skilled mechanic to operate it and bring out 
all its capabilities, almost anything in the line of tool-making 
and machine construction may be accomplished. As to-day lathes 



38 TOOL-MAKING AND 

are being built in the most astonishing variety of capacities, from 
the delicate precision-lathe to the ponderous three-hundred tons 
gun-lathe, no difficulties should be experienced in procuring one 
for any special line of tool -making or manufacturing. 

After the lathe, next in importance comes the drill-press, the 
selection of which depends upon the class of work to be done. 
Usually there should be two a small sensitive drill and a large 
column machine. Next we have the universal milling-machine, 
with its boundless possibilities. In order of importance the 
shaper and planer come next, and in their choice the nature of 
the work to be done is also the chief factor to be considered. 
Vises and small tools, of course, follow; then the speed-lathe, 
for hand-tooling, polishing, and lapping. Lastly, the modern 
tool-room is not complete without a tool-grinder. All of these 
machines are sufficiently well known and a detailed description 
of any would only take up valuable space. 

In regard to a tool-room of the second class, it must be obvi- 
ous to all that its chief requisites are that it shall form a conven- 
ient place where tools and appliances may be systematically 
and handily distributed. In a small establishment only one tool- 
room is necessary, but in any extensive establishment, where 
there are several buildings and several floors in each building, it 
is necessary that there shall be a number of tool-rooms in order 
that there shall be convenience in the distribution of the tools. 

In order that the reader may understand what a tool -room 
should be like, it is essential that a short description of a model 
one should be presented. I know of no better way of doing this 
than by describing those in the" shops of Brown & Sharpe, Provi- 
dence, R. L, U. S. A. In their shops the different tool-rooms 
are much alike, the largest one being on the second floor of the 
main building, where all lathe tools are ground on a Seller's 
grinder before being given out, and other work of like character 
done. Like all shops in which large numbers and varieties of 
tools are in use, the check system is in use. Ten checks are giv- 
en each workman, one of which is placed opposite the place re- 
served for any tool that he has out. One noticeable and excel- 
lent feature of these tool -rooms is the good supply of parallels in 
each. To save checks, when a workman requires several paral- 



INTERCHANGEABLE MANUFACTURING. 



39 



lels the system shown in Fig. 11 is in use. The parallels are placed 
in pigeon-holes, those of one size in one row, the next larger in a 
row below, and so on. At the right is a board, on the side of 
which is marked the size of the parallels in each row, and at the 
top of which are the numbers 1 to 6, to indicate the number of 
parallels in use. Checks in the positions shown would indicate that 
a workman had out four 1^-inch parallels and three 2f-inch ones. 
In a great many shops it is common to keep the tool -rooms 
supplied with sets of taps and tap-drills together in two blocks, 



Q 



U 



n 



12345 
l" 






etc. 

2x2". 



2H--^- Q - 



FIG. 11. 

only one check being necessary to secure the whole. In the 
Brown & Sharpe tool-rooms the tap blocks are more completely 
equipped than usual. Each set or block consists of a full set of 
drill, tap-drill, starting, sizing, and bottom -tap, two counter- bores 
for holes where countersunk head -screws are used, one counter- 
bore having a tip the size of a standard hole and the other to fit 
a tap-drill hole ; each block also contains a test plug, giving the 
size of a standard head for screws of that size and a tap -wrench. 
In regard to keeping track of workmen's supplies, there is a 
novel system in use. It consists of a six-sided case, one in each 
tool-room, on the sides of which hang an extra size of ten checks 
for each man. The top of the case is divided into several com- 
partments, marked, respectively, "Oil," "Waste," "Towels," 
"Emery Cloth," etc., and when a man wants a ball of waste one 
of his checks is dropped into the receptacle bearing this name. 
Thus after a certain time has elapsed the checks may be removed, 
counted, and a record taken of the amount of supplies which each 
man has used. The checks are then put back on their pins. 



CHAPTER III. 

Fundamental Principles, Processses and Practical 
Points for Jig Design and Construction. 

BEFORE taking up the various types of jigs and fixtures used 
for the production of repetition parts by drilling and milling, 
and illustrating them and describing their construction and use 
in detail, I have thought best to devote a chapter to a presenta- 
tion of the fundamental principles, various processes, and prac- 
tical points which are required to be understood in order to suc- 
cessfully design and construct drilling jigs and fixtures or 
similar special tools used for the machining and duplication of 
machine parts. If the rules laid down are followed, much un- 
necessary labor and expense will be avoided and the best of 
results attained. The descriptions are given from an entirely 
practical point of view, the theoretical not being touched upon 
and anything purely speculative being omitted. 

FACTOES INVOLVED. 

In the first place, let it be understood that there is no one 
other branch of the machine business that requires more thought, 
wider knowledge, and broader experience of shop conditions than 
the designing of jigs and fixtures, and in order for one to be 
competent to do this work successfully he must possess this essen- 
tial knowledge of shop conditions. To those who are not so 
equipped a close study of the chief factors and the fundamental 
principles involved will be of untold value. 

In jig and fixture w r ork there are six highly important factors 
to be considered: 1. The course the work is to follow during 
manufacture. 2. The locating and securing of the work in the 
fixtures. 3. Keeping of the locating points for the work free 
from chips and dirt. 4. Self-contained tools. 5. The class of 
help that will use the tools. 6. Convenience and ease in hand- 
ling the tools during their operation. 

40 



INTERCHANGEABLE MANUFACTURING. 41 

Taking the first factor the course of the work during manu- 
facture we will say that a part of a machine is given us to design 
tools for its production in repetition. Now say that/ the part, in 
order to complete it, will have to go through two operations, 
drilling and milling. The question is which should be done 
first, the drilling or the milling ? 

In most cases where the part is to be drilled and milled, it is 
best to provide for doing the milling first ; because it is desirable 
that the drilled holes and milled surfaces shall bear a certain 
definite relation to each other, and because by having the holes 
drilled from a milled surface greater accuracy and interchange- 
ability in the parts can be obtained than if the milling were at- 
tempted after the drilling of the holes. However, in order to 
decide the question, a u working point or surface" must be de- 
cided upon. Whether the part to be machined is a casting or 
not, there is always one point which from its position that is, in 
relation to others should be taken as a " working point," a point 
to work from and refer to in all subsequent operations required 
to manufacture the particular part. The point chosen may be a 
hole, a plain surface, a slot, or a lug or a boss it matters not. 

THE LOCATING AND HOLDING DEVICES. 

Now having chosen the working point, it follows that this is 
the point to be machined first, and that the first jig or fixture to 
be made is the one for this operation. This is the secret of suc- 
cessful jig-making. Also use this point for the locating of the 
work in the different jigs and fixtures for subsequent operations. 
Never change a working point, as the performing of one opera- 
tion from one point and the next from another is not conducive 
to good results. 

When designing fixtures for drop-forgings, turned work, 
punch-blanks, or any part that has been previously put through 
a cutting, abrading, compressing, or forming operation, the con- 
tour of the part is usually such that the holding of it is a simple 
matter, especially if the first operation is to be a milling cut. 
With eastings, however, through their lack of uniformity in 
many cases, fixtures of intricate and costly design are required, 
thus necessitating considerable care and judgment in the devising 



42 TOOL-MAKING AND 

of the locating and holding means. If, instead of milling, it is 
decided that the drilling should be done first, and that the holes 
so produced are to be used in locating and securing the work in- 
stead of using the outline, it will be found that a simpler and less 
costly fixture can be used. Whichever course is decided upon, 
the fixtures should be so designed as to allow of all operations of 
one class being completed before commencing on another class. 

Now in regard to locating and securing the work quickly, ac- 
curately, and easily, these are factors of the greatest importance, 
and it is difficult to discuss them properly, for the efficiency of 
the finished work depends more than anything else upon them. 

The various methods in universal use for locating and fasten- 
ing the work to be machined in jigs and fixtures, such as bunters, 
cams, set screws, spring pins, slides, flat taper pins, etc. , are well 
known, and I will not attempt to lay down a general rule for 
their application, as this must be decided by the designer accord- 
ing to the type of fixture and the nature of the work. 

One of the most essential conditions necessary to the accurate 
and rapid production of work in jigs and fixtures is convenience in 
keeping the locating point free from dirt. This must be evident 
to any one at all familiar with the use and object of such tools. 

When I state that tools should be self-contained, I mean that 
all devices and means utilized in the locating and securing of the 
work should be component parts of the tool. When this is the 
case, the operator is not obliged to use a hammer, wrench, or 
any other tool in order to operate the fixture. 

SIMPLE DKILLBs T G-JIGS. 

When drill-jigs of the comparatively simple types are to be 
constructed for the machining of parts in which no great accu- 
racy is required, the main point to be considered is the inter- 
changeability required in the work after it is machined. With 
this point constantly in mind, the avoiding of all unnecessary 
expense and labor will not be difficult. In the construction of 
simple jigs, which are to be used for the drilling of parts which 
have been first finished at one or more points, or for rough cast- 
ings which have not had any previous machining, the most essen- 
tial points necessary to their successful construction and use are 



INTERCHANGEABLE MANUFACTURING. 43 

as follows : First, in making the patterns construct them so as to 
leave openings in the castings at all points wherever possible, 
without affecting the strength or rigidity of the castings when 
finished, for the escape of the chips and dirt. Second, provide 
spots with just surface enough to allow of their rapid surfacing. 
Lastly, so design the jig as to allow of the expeditious fastening 
and locating of the work and its removal when finished, as this 
is one of the important factors in the operation of such tools. 

CONSTRUCTING SIMPLE JIGS. 

When constructing, after having done the preliminary ma- 
chining of all necessary outside points, choose the most reliable 
and positive points for locating the work. First, a machined 
surface for the positive points for locating. When this is not 
possible, those points in which the minimum of variation is to be 
expected in the castings should be chosen. Then, in the fasten- 
ing of the work within the jig, use means which will be the 
quickest in operation consistent with all possible simplicity. 
As there are any number of simple and inexpensive devices which 
can be adopted to allow this, it should not be difficult. 

One point which cannot be too strongly impressed on the de- 
signer of simple jigs is to allow excess of metal at as few points 
as possible ; that is, only at the locating and squaring surfaces. 
The all too prevalent habit of leaving unnecessary surfaces to be 
finished is expensive and not consistent with satisfactory results. 

PROCESSES OF ACCURATE JIG-MAKING. 

When drill- jigs are to be made for the drilling of work in 
which the utmost accuracy is desired, the locating and finishing 
of the bushing-holes is of the greatest importance, and for that 
reason I give here descriptions of the most rapid and practical 
methods for the accomplishment of this part of the work. 

THE BUTTON METHOD FOR LOCATING DRILL 
BUSHING-HOLES. 

In the first place, if the jig to be made is of the box type 
which is the most generally used type for which the body cast- 
ing has been secured, after all sides and bearing surfaces have 



44 



TOOL-MAKING AND 



been planed or milled square and true with each other, including 
the feet, it should be rested on a surface plate, as shown in Fig. 
12, which should be used only for work of this class. If the feet 
are cast on the jig, they should be scraped until the sides of the 




SURFACE PLATE 



FIG. 12. 

body portion are at perfect right angles with their bottoms and 
until all legs rest perfectly square on the surface plate. If the 
feet are of tool steel and are screwed into the jig, they should be 
hardened and lapped on a flat lapping-plate (as shown in Fig. 
13), until the same results are accomplished. This preliminary 




FIG. 13. 



work on the jig is the basis for the successful attaining of all 
other results, and unless done carefully there is no possibility of 
the remainder of the work being accomplished accurately. 

For the laying out or locating of the bushing-holes in jigs, and 



INTERCHANGEABLE MANUFACTURING. 



45 



the finishing of them, there are any number of methods in use 
among tool-makers. Some of these methods allow of fair results 
being attained, while others are useless, and when accurate or 
satisfactory results are accomplished though their use it is pure 
luck, not the method that does it. There is only one method for 
locating bushing-holes in small and medium-sized jigs accurately 
and expeditiously. 

The following method is used by the best tool-makers on this 
class of work and is known as the " button method " : In shops 
where jigs for accurate production are constructed, a few sets of 
locating buttons should be kept in the tool-room as standard 
sizes say, five-sixteenths, one-half, and three-fourths inch in 
diameter, as shown in Fig. 14. They should be of tool-steel and 
finished to from one -half to one inch in length, and should have 



ing Screw 




Countersunk End 




FIG. 14. 



a hole through them large enough to allow about three-sixty- 
fourths inch clearance for the fastening screws, after which they 
should be hardened and then ground perfectly square on each 
end, and on the outside to standard size, finally lapping them to 
get them accurate. One end of the button should be slightly 
countersunk, so that it will rest squarely on the jig when in posi- 
tion. The centres for the bushing-holes in the jig should next be 
located approximately correct by the dividers and then prick- 
punched. They should then be drilled and tapped for the button 
screws. 

To locate the holes positively, first secure a button in position 
by working from two sides of the jig, using a Brown & Sharpe 
height-gauge, and fasten it securely by tightening the button 
screw. Locate the next hole in the same manner, using the height 
gauge or vernier gauge to get the buttons exactly the proper dis- 



46 



TOOL-MAKING AND 



tance apart and from the sides of the jig, the hole in the buttons 
being sufficiently large to allow of adjusting them in any direc- 
tion. After having set the buttons to the number of holes re- 
quired, and having fastened them securely, as shown in Fig. 15, 






FIG. 15. 

the finishing of the holes is in order. This may be accomplished 
by strapping or clamping the jig body or lid, as the case may 
require, on the lathe face-plate, being careful not to spring it, 
and then truing the first button by the use of a centre indicator 
or "wiggler," as shown in Fig. 16. The button should then be 




Slide Rest 



FIG. 16. 



removed and the hole bored and reamed to the finish size. Then 
shift the jig, locate the next button perfectly true, and repeat 
the boring and reaming operations ; and proceed in this manner 
until all the holes required have been finished. By the use of 



INTERCHANGEABLE MANUFACTURING. 47 

this method jigs of the greatest accuracy can be successfully con- 
structed without trouble and worry on the part of the tool-maker, 
and the results in the castings to be machined in them will be a 
foregone conclusion. 

PATTERNS FOE CASTINGS TO BE JIGGED. 

In order to produce good work from intricate jigs, it is abso- 
lutely necessary that the castings to be drilled in them should be 
of uniform size and shape. To insure this, the patterns from 
which they are cast should be of metal in all cases, finished at all 
points to the size required ; allowing, of course, for shrinkage 
and surplus stock at all points which are to be machined pre- 
vious to drilling. When perfect patterns are made there will be 
no doubt as to the results in the castings. 

If the method described in the foregoing for the locating and 
finishing of the bushing-holes in small jigs of the accurate types 
were more generally known and used by tool -makers, there 
would be less worry in the accomplishment of successful results 
than is at present experienced in the effort to obtain the same by 
methods which are now obsolete. 

Besides the locating and finishing of the bushing-holes in the 
most accurate manner, the following must be kept in mind in 
order that satisfactory .results will be attained in jig-making. 
All the various parts of such jigs, including the body castings, 
should be made sufficiently heavy and strong to withstand all 
strain to which they may be subjected when in use. The man- 
ner of locating the work within the jigs should be such as to be 
positive and to eliminate the possibility of shifting during the 
operation of the tools. For instance, it would be ridiculous to 
adopt a device of the same strength for fastening a piece in 
which a one -inch hole is to be drilled as would be used for hold- 
ing a piece in which a one-half-inch hole is required. The means 
and points chosen for the fastening of the work within the jigs 
and against the locating points should be such as to allow of 
rapid manipulation and in no way to interfere with the drilling ; 
and, lastly, the design and construction of the tools should be 
such as to dispense with all unnecessary parts and labor. 



48 



TOOL-MAKING AND 



LOCATING AND FINISHING DEILL BUSHING-HOLES 
IN LAEGE JIGS. 

The following method of locating and finishing bushing -holes 
pertains to large jigs. As a rule, the castings of large jigs for 
machining heavy parts are of considerable size and weight. It is 
not always possible to swing them on the lathe face-plate and fin- 
ish the bushing-holes by the "button" method; as the cumber - 



VERTICAL 
ATTACHMENT 




MILLER 
TABLE 



FIG. l", 



some shape and unusual size of the body castings interdict the 
accurate and positive locating of the buttons and make the task 
wellnigh impossible, we are forced to adopt other means which 



INTERCHANGEABLE MANUFACTURING. 



49 



will allow of accomplishing the result in an easy manner. To do 
this we use a universal milling-machine which is equipped with 
a vertical attachment. First, we strap the jig body on the table 




FIG. 18. 

and then locate the holes by using the cross and longitudinal feed- 
screw graduations, the vertical feed, a pair of twelve-inch ver- 
niers, and a B. & S. height-gauge. The actual work is accom- 
plished by first locating and finishing the holes in the upper 
surface of the jig body, using a small drill-chuck, as shown in 
Fig. 17, located hi the socket of the vertical attachment, and a 
short, stiff, centering drill. We space, centre, and drill the 
holes to the number required in their approximately correct po- 
sition, leaving them somewhat uuder-size and in their accurate 
location to each other. To size and finish the holes, a spindle 
should be turned to fit the socket of the vertical attachment and 

a small cutter inserted in the protruding end of it. Thus we 
4 



50 TOOL-MAKING AND 

have a small boring-bar, as shown in Fig. 18. We next deter- 
mine the distance from the side of the boring-bar to the working 
side of the jig body with verniers. We deduct one -half the di- 
ameter of the boring -bar and then move the table by means of 
the cross and longitudinal feed-screws the distances required in 
thousandths, and bore the hole to the finish size. The hole being 
finished we make a plug and fit it to the hole and insert it, and 
then finish the remaining holes by working from the plug and 
the side of the jig, measuring with the verniers from the side and 
from the base with the height-gauge. Afterward we may drill 
and finish the holes in the other sides of the jig body in the same 
manner, merely reversing the jig body or removing the vertical 
attachment and working directly from the miller-spindle, as may 
be found convenient. 

JIG WOEK OX THE PLAIN MILLIXG-MACHIXE. 

While the most satisfactory and accurate results in jig-mak- 
ing can always be attained on the lathe face-plate by the "button 
method " or on the table of the universal milling-machine by the 
vertical attachment, as described in the foregoing, and jobs can 
be done that would be wellnigh impossible of accomplishment 
by other means, it must not be inferred that the plain milling- 
machine is limited in its sphere of usefulness in jig-making. 
Practice has proven that this machine tool possesses considerable 
utility in this line. 

As the greater number of jigs required are rectangular and 
have bushing-holes let in parallel with the sides, and not infre- 
quently the bushing-holes are located in all sides of the jig body, 
with eacli side used in turn as a bottom to set the jig on when 
drilling from the opposite side, it Avill be apparent that a large 
part of the work necessary to construct the tool can be conven- 
iently done on a plain miller with a table that can be adjusted 
vertically. We will say that we have a jig to make with bush- 
ings let in from two parallel sides. First we square and scrape 
the bottom locating surfaces and then clamp the jig body on the 
plain miller-table, setting it square with the spindle and as far 
from it as possible, so that we may have ample room between it 



INTERCHANGEABLE MANUFACTURING. 



51 



and the work. In some cases it may be expeditious to clamp an 
angle-plate to the platen at one side of the work square with the 
spindle, so as to assist in locating the first hole and proving the 
work as we proceed. If holes are to be put in all of the differ- 
ent sides and the jig is clamped for locating the holes in the 
second side, the tool-maker can establish without trouble the 
correct relation between the holes by taking distances from the 
angle-plate to plugs inserted in the holes first bored, as per Fig. 
19. When the distance from the first hole to the side of the jig 
is determined, we add the distance the jig is from the angle- 
plate, and thus determine how far the first hole is from the angle- 




FIG. 19. 

plate. With the rest of the work there are a number of ways to 
follow, but the most practical is to use the height-gauge to meas- 
ure all distances. Another, that is almost as good, is to insert 
an arbor in the miller-spindle and feed the table forward until a 
piece of tissue paper will just draw out between the arbor and 
the angle-plate. Then by means of the dial on the longitudinal 
feed-screw run the table forward the required distance. When 
the screw on the machine has been determined to be correct, one 
can depend on the dial almost wholly for the vertical spacing, 
while the platen can be set by calipering to the arbor in the 
spindle. 

In doing jig work on the plain-miller a parallel can often be 
clamped to the side of the jig, from which measurements may be 
taken. After the work has been located in place on the table a 
miller-vise may be clamped to the platen and a diamond-point 
tool clamped in it, with which the test arbor in the spindle may 



52 



TOOL-MAKING AND 



be turned true, as shown in Fig. 20, finishing it to size conven- 
ient to use in locating the work both horizontally and vertically. 
Then again, a turning-tool may be clamped to the back edge of 
the table with a parallel spanning the distance to the first slot in 



Jig Body 



Test Arbor 




FIG. 20. 

the table, and in this way true a piece of stock which may be 
held in a chuck in the spindle. Any tool-maker who has done 
much jig work on the miller will appreciate the advantage and 
the help in having a test piece in the spindle running perfectly 
true, and that in order to accomplish accurate work it is neces- 
sary to have all conditions equally accurate and reliable as the 
job progresses. 

It is sometimes necessary to bore a bushing-hole in a jig at 
an angle with one of its sides. To do this correctly on the plain 
miller we can set the jig body at the given angle with the angle- 
plate which has been first set square with the spindle by a 
bevel protracter. 



HAXDLIXG LABGE JIG BODIES. 

When work is to be handled that is larger than the capacity 
of the milling-machine platen, it is only necessary to provide an 
auxiliary platen almost as long as the machine table and about 
twice its width, and bolt it to the machine. This emergency 



MANUFACTURING. 



53 



table should be provided with a number of slots or holes for fas- 
tening the work to it. Accurately made parallels which just fit 
the slots in the table are of great convenience in setting such 
large work, while a block with a tongue to fit the slot and nearly 
as wide as the table and with its edge milled accurately in line 
with the spindle axis is also a help. 

After the jig is located and ready for letting in the bushing- 
hole (whether on the lathe face-plate or on the table of the uni- 
versal or plain milling -machine), finishing should not be done 
with drill or reamer, for there will not be one chance in a thou- 
sand that the hole will be accurately located. The hole must be 
bored to a finish in order to do a correct job. 



JIG FEET. 

The proper feet for jigs is largely a matter of individual 
taste. There are, I believe, quite as many kinds of jig feet as 
there are jig designers. Some even go so far as to prefer having 
no feet at all on their jigs, and thus obviate the possibility of 
trouble with the drill-press table slots. 

Figs. 21 to 30 show a number of different kinds of jig feet. 
Figs. 21 and 22 are flat-base types; Figs. 23 to 25, cast feet on 




J 



U 



FIG. 21. 



the base of jigs. Any of these make good feet, the one shown 
in Fig. 23 being, of course, easier to make and just as good as 



TOOL-MAKING. 



the others except where a foot of considerable length is neces- 
sary. With steel feet all sorts and sizes are used and give satis- 
faction. Figs. 26 to 30 are types. 

In concluding this chapter it will not be amiss to emphasize 
the advisability of becoming practically familiar with the instal- 





FlG. 23. 



FIG. 24. 



lation and operation of the interchangeable system of manufac- 
turing. To demonstrate the necessity of mastering the details of 
the system, it is only necessary to point out that in the manufac- 
turing machine-shop of the present day the efficiency of the ma- 
chines or parts turned out can usually be judged by the use that 
is made of properly designed and constructed drilling and milling 
fixtures and jigs for the production in repetition of the most 




FIG. 25. 

accurate operations of the work. Although it has been, and is 
still, possible to obtain satisfactory results without a large outfit 
of such tools, no shop can produce interchangeable parts or du- 
plicate machines in large quantities and sell them at a price 
which will compete in the open market, unless it has an ade- 
quate equipment of special jigs and fixtures, and a man at the 
head of it who thoroughly understands their design, construction, 
and use. 





FIGS. 26-30. 



CHAPTER IV. 

Types of Simple and Inexpensive Drilling-Jigs ; 
Their Construction and Use. 

IN order to discuss the subject of drilling-jigs exhaustively, 
I think it is best to follow up the chapter devoted to the funda- 
mental principles for such work by first taking up the compara- 
tively simple class of such tools which are used for the machin- 
ing and duplication of parts in which great accuracy is neither 
essential nor desirable. As before stated, the main point to be 
always considered by the constructor of tools of this class is the 
degree of variation allowable in the work that is to be machined. 



TWO TYPES OF VEEY SIMPLE DEILLIXG-JIGS. 

Fig. 31 is a plain casting with two ribs cast 011 one side. The 
casting is first planed on the sides A A, and a cut is also taken 
off the ribs. It is then ready to be drilled. As the holes to be 
drilled are clearance holes for bolts and studs, no great accuracy 
in the jig is required. The jig for this casting is shown in three 

views in Fig. 32, and, as will be 

A A 

seen, is about as simple and in- 
expensive to construct as could 
be devised for the work. It con- 
sists of one body casting, D, with 



i 




oc 


! 






c 




1 




ed 





c 


oi 
c 


OB 


! 












B C 



C B 



FIG. 31. 



six projections on one side for 
the locating-points and fasten- 
ing-screws. It is first planed on 
the top and then strapped on an 
angle-plate on the miller-table, and the inside is milled. The 
inside of the projections F. and E E are finished square with 
each other, as they are the locating-points. Holes are then 
drilled for the set-screws J and I I in the lugs G G and H re- 
spectively. These screws are case-hardened. In locating the 

55 



56 



TOOL-MAKING AND 



holes for the bushings, a casting, planed and ready to be drilled, 
is laid out, and the holes are drilled and reamed in the posi- 
tion and to the size necessary, so that they will coincide with 
those in the part of the machine on which the casting is to be 




FIG. 33. 

fastened. This casting is then used as a templet, and by 
means of the screws J and / I fastened within the jig. The 
holes are then transferred through it to the jig, enlarged, and 
reamed to size. The bushings L L L L and K K are then made, 
and hardened, lapped, and ground to size, and finally driven 
into the jig. The castings are drilled by fastening them within 
the jig and resting them on the face of the ribs. This jig is easy 
to handle and is a rapid producer. 

The jig used for drilling the holes P P and 0, in the casting 
Fig. 33, is of a different type and is known as a "box- jig." It 
is in design one of the simplest and most reliable of jigs suitable 
for drilling work of the class shown, where holes have to be 
drilled at right angles to each other. The casting Fig. 34 is 
machined at one point only, J/ M, before drilling, by means of a 
gang of mills, the size being exact and the ends square. This 
milled surface is utilized as a locating-seat for the work when 
being drilled. The jig Fig. 34 is in two parts the body or box 
casting A and the lid E. The body casting is first planed square 
on all sides, and the inside at C C finished oft' to fit the milled 
portion of the casting at M 31. A cut is also taken off the back 



INTERCHANGEABLE MANUFACTURING. 



57 




O! 

O! 

*"*! 

Oi 

O! 



at D for the side-locating point for the work. The lid E is fast- 
ened to the body casting at each end by means of the screws and 
dowel-pins. Two holes are then drilled 
and reamed through the lid E and the 
base A for the taper locking-pins I J, 
which are of Stubs steel and are 
milled flat on one side and hardened. 
The centres for the two bushings G 
G in the side of the jig, and the four 
// II H II in the lid are accurately 
located by setting the jig on the sur- 
face-plate and locating the centres by 
the use of a Brown & Sharpe height-gauge. The centres are then 
prick-punched, and circles, of the diameter to which the holes are 
to be finished, struck around them with the dividers, ^ow when 
holes are to be bored an exact distance apart that is, to the 
smallest possible fraction of an inch the only way to accomplish 







FIG. 83. 




B 



this successfully is to use buttons and to strap the jig on the 
face-plate of the lathe, and accurately locate them by means of an 
indicator; but in a jig where a generous limit of error is al- 
lowed, as in this case, a simple and more expedient means may 



58 TOOL-MAKING AND 

be used. The best and most reliable way is to strap the jig on 
the table of the miller and locate the drill true and central with 
the reference hole, after which the other holes may be located by 
moving the table forward or backward, or raising it the proper 
distance, by means of the dial on the feed-screws. In fact, all 
bushing-holes in jigs of this kind should be drilled in this man- 
ner, and not on the drill -press, as it is pure luck when satisfac- 
tory results are attained with the latter method, and that factor 
is a poor and unreliable one to depend on. After the bushings 
are made, hardened, and driven into their respective positions, 
as shown, and the clamping-screw J made and entered into the 
lid E, the jig is complete. 

To use the jig the casting Fig. 33 is slipped into it so that the 
points M M are located at C in the jig. The clamping-screw 
J is then tightened and the two taper-pins entered with the flat 
face of each against the work, and each given a sharp blow Avith 
the hammer to locate and hold the work tightly and positively 
in position. The jig is then stood up on the legs B B, and the 
four holes O are drilled. It is then turned on its side, 
and the two holes P P, Fig. 33, are drilled. The clamping-pins 
II are driven out and the screw J loosened, the finished work 
removed, and another casting inserted. The use of the taper 
locking-pins II, as shown, is one of the quickest and most posi- 
tive means for the fastening and locating of work of the class 
here mentioned. 

The two jigs described embody in design and construction a 
number of different practical points which can be adapted for 
use in jigs for the drilling of parts which have first been finished 
at one or more points, as well as rough castings which have not 
been finished at all before being drilled. Of course, for the lat- 
ter class of work, except in special cases, jigs of the simplest and 
most primitive design are all that is necessary, and they are not 
worthy of a detailed description. 

A SIMPLE FOURTEEN-HOLE DRILLING-JIG. 

Fig. 35 shows a casting used as a leg of a small automatic 
machine, and the jig for drilling the holes in this casting is of a 
more accurate and complicated design than the two previously 



INTERCHANGEABLE MANUFACTURING. 



59 



shown, as the holes drilled in the bosses A B C D are for shafts, 
and must be exactly the proper distance apart for the gears, 
which are afterward assembled on the shafts, to mesh properly. 
The casting, Fig. 35, is first machined to size at four points, 
namely, at the top and bottom and both sides of the bosses. In 
all there are fourteen holes to be drilled, in the positions shown. 
The jig used in drilling the holes is illustrated in three views 
in Fig. 36. Fig. 37 is a plan of the jig. These show clearly the 
design and construction, and very little description is necessary. 





FIG. 35. 

The jig proper A is of the box type, and is made with the re- 
movable lid D. It is cast with legs on three sides at both ends, 
at B B, and at the bottom, at C C. All sides are first machined 
square. On the inside of the jig, at E E E E, are raised spots 
for the work to rest on. This allows of quickly finishing the 
inside, by merely milling the face of the spots to the height de- 
sired. The locating-points for the work are four; the two ad- 
justable locating-screws H II, which are equipped with jam-nuts 
II, and the points at 8 8. The adjustable screws should always 
be used when castings of the kind shown are to be drilled, as 
any variation in the different lots of castings may be quickly ac- 
commodated by adjusting the screws. For locking and fasten- 



60 



TOOL-MAKING AND 



ing the work against the locating-points, and within the jig, two 
set-screws, K and M respectively, and the eccentric clamping- 
lever J are used. The set-screw M holds the casting squarely on 




PLAN VIEW WITH LID OFF, 

8HOWJNQ MANNER OF LOCATING, 

AND HOLDING WORK. 




FIG. 36. 



the raised spots in the jig, and that of K forces it against the 
points at 8 8, while by giving the lever J a sharp turn it forces 
the casting against the screws II II and locks it in position, there- 
by holding the work securely without danger of loosening while 
being drilled. The eccentric clamping-lever is rapid in both 
fastening and releasing the work. The lid D is located on the 
jig by means of the dowel-pins G G, as shown in Fig. 38, and 
fastened securely by the swinging clamps L L. 

In this jig the holes for the bushings at either end, for drilling 
the holes marked G and irrespectively in the work Fig. 35, are 
drilled in the milling-machine in the same manner used for the 
other jigs. But for the shaft-holes ABC and 7), after the but- 
tons are accurately located, the lid I), Fig. 37, is strapped 011 the 
lathe face-plate, and each "button" positively located with an 



INTERCHANGEABLE MANUFACTURING. 



61 



indicator, and the holes bored and reamed to the finish size for 
the bushings P P P P and E E respectively. 

When using the jig the lid D is removed and the casting in- 
serted within the jig, as shown as Q, Fig. 36. The lid D is then 
replaced, locating on the dowel-pins G G, and the swinging 
clamps L L are tightened. The set-screw M is also tightened and 
the eccentric lever J given a sharp turn to locate the casting 
tightly in position. The holes at either end are drilled by rest- 
ing the jig 011 the legs B B. The casting is then rested on the 
legs G (7, and the six holes in the side are drilled. The removal 
of the finished work may be quickly accomplished by loosening 
the set-screws K and M and the lever J, and then removing the 
lid D. 

The three jigs shown and described in the foregoing will 
serve as practical illustrations of three separate and distinct 




types of jigs, and show how, by the use of simple and inexpen- 
sive tools, uniform and satisfactory results may be obtained at 
the minimum of cost and to the maximum of production in the 
machining of parts in which, as stated before, a limit of error is 
allowed. 



62 



TOOL-MAKING AND 



JIGS FOE A BEAKISTG-BBACKET AND BEAEING. 

Fig. 38 shows a casting of aluminum, used as the upper bear- 
ing bracket of an electric cloUi-cutting machine. After the hole 
in the centre had been bored and reamed to fit the bearing, Fig. 
40, at K, it was faced off on the front and back. The holes in 
the wings were to be all interchangeable with those in the motor- 
case of the machine. The four holes around the centre were also 
to be interchangeable with those in the bearing, Fig. 39. All 
these holes were drilled in the jig Fig. 40. This was made in 
two parts, the base A and the lid B. For these patterns and 
castings were made. There were four bosses in the bottom for 
the work to rest on while drilling. After the base A had been 
faced off on the back, it was strapped in the miller and a cut 
taken over the bosses and also over the ends on which the lid 
rested. A hole was then drilled in the centre of the base, into 
which a plug, E, of tool steel, turned to fit the centre hole in the 
work (Fig. 39), was driven. The work was then placed 011 it and 
the stop-pin G let in. The set-screw E having been made, a hole 
was drilled and tapped and the screw let in. 

The lid B, of cast-iron, after being planed on both sides was 
strapped to the top of A, and holes were drilled for the two 





FIG. 38. 



FIG. 39. 



dowel-pins C C, which were then let through into A, and the 
holes in B eased up so that the lid would set in nicely. A and 
B were then clamped together and a slot milled through each end 
for the locking-posts II. The posts were made and finished and 
hinged in A by pins J J. Thumb -nuts were got out and tapped 
to screw on to the posts freely. The posts were then swung over 



INTERCHANGEABLE MANUFA CT URISG. 



63 



and the thumb-nuts tightened, thereby clamping the lid and base 
together. The jig was then stood up on the side D, which had 
been squared with the back, and the centre of the stud E was 
found on the lid B with a height-gauge, the holes for the bush- 
ings were laid out, centred, drilled, and reamed, and the bush- 




FIG. 40. 

ings made, hardened, ground, and driven in. The jig was then 
complete, and lid was removed, and the work (Fig. 38), was in- 
serted, centring itself on the stud E. The set-screw R was 
tightened until the work was forced up against the stop-pin G, 
the lid B was replaced, the dowel-pins C C locating it, the lock- 
posts were swung up, the nuts tightened, and all the holes 
drilled, which completed the operation. As will be seen, there 
is just enough space between the bottom of the lid and the \vork 
for clearance, which was all that was necessary. The centre 
holes in the castings being reamed to the size and as nearly as 
possible in the centre, thereby fitting the stud E, and the cast- 
ings being of uniform size, they were easy to handle. The stop- 
pin G and the screw R were sufficient for all requirements of 
location. Clearance-holes were drilled in the bosses on which 
the work rested, to allow an easy escape for the drillings. 

Fig. 41 shows the jig used for drilling the four holes in the 



64 TOOL-MAKING AND 

bearing, Fig. 39. As stated before, they had to match those to 
the bracket, Fig. 38. The bearing itself was of tool steel, turned 
and finished all 'over to fit the centre hole in Fig. 38. The jig 
for drilling was of the box type, made in two sections. L was 
the base or jig proper, of round machinery steel, a piece of which 
was chucked and turned on the outside and a hole bored and 
reamed to just fit the work at K. It was secured and a thread 
of a coarse pitch cut, leaving only two threads. It was then 
faced off and undercut at the bottom, to allow the work to set 
in, as shown. The lid P was turned and threaded to fit the 
piece L nicely ; it was also couuterbored to go over the work 
and clamp the face when screwed down solid. The outer edge 
was heavily knurled to give a good grip. The work (Fig. 39), 
was inserted into one of the finished pieces 
(Fig. 38), and the four holes were transferred 
through it, when it was removed and inserted 

in the jig L and used as a templet, and the 
FIG. 41. 

holes drilled through it and through the bot- 
tom of the jig L. The top P was then screwed on and the holes 
transferred to it. Then they were enlarged for the bushings, 
which were made and driven in. This finished the jig. The 
work being inserted, the cap was screwed down and the holes 
were drilled. 

TWO SIMPLE DBILLIXG-JIGS A:N T D THEIE USE. 

In Figs. 42 and 43 respectively are shown two examples of 
the duplication of work by drilling by the use of jigs of the sim- 
plest possible construction. The work for the drilling of which 
these jigs were used is also shown, both jigs being used on the 
same piece of work. Although no great degree of accuracy is 
required in the location and size of the holes drilled, the use of 
the jigs saves considerable time and insures the desired degree of 
interchaugeability in the work. 

The points drilled in the work by the use of the jig shown in 
Fig. 42 are four holes at D D D D, within A A ; and, by the jig 
shown in Fig. 43, a hole through each of the legs B B. The 
construction and use of these two jigs can be clearly understood 



INTERCHANGEABLE MANUFA CTUEING. 



65 



from the illustrations, as well as the manner of locating and fast- 
ening them to the work. As shown, the usual conditions are 
reversed, the jigs being located and fastened on the work instead 




FIG. 42. 

of the opposite, which is usually the case. The jig shown in 
Fig. 42 consists of seven parts. The bushing and locating-plate 
C is of machine steel finished on the ends so as to fit easily into 
the portion of the work between A A. The four holes for the 
drill-bushings are located and bored and reamed to size, and the 
four hardened bushings forced in. A hole is then drilled and 
tapped in the centre of the side C. to admit the stud E. This 




II 




FIG. 43. 



stud has about one inch of thread on the outer end for the fast- 
ening nut F, which is finished to the shape shown and the outside 
heavily knurled. When drilling, the casting, or work, is stood 



66 



TOOL-MAKING AND 



up on the drill-press table and the jig located between the points 
A A, as shown, and the nut F tightened against the opposite 
side. The four holes are then drilled through the drill -bushings 
and the jig removed by simply loosening the nut F. 

The second jig, shown in position on the work and in a side 
view in Fig. 43, is of such simple construction that it can be un- 
derstood from the illustrations. The three pins 1 1 Jaiid J J J 
respectively, at either end of the bushing-plate G, locate the jig 
on the legs B B of the work, and the two holes are drilled 
through the bushings H H. 



TWO DEILLING-JIGS FOE THE SPEED-LATHE. 

In Figs. 44, 45, and 46 are shown views of two drill -jigs of 
rather novel character, suggestive of ways of drilling a large 
variety of different shaped pieces. Fig. 44 is used for drilling 
the hole a in the brass piece A (Fig. 45) used for a basin plug, 
a rubber washer being afterward fastened around the neck, the 
a hole being for the chain ring. 

For this jig a piece of 1-inch round machine steel was turned 
with a taper-shank to fit the tail-spindle of the speed-lathe, 
and a hole was drilled through the body at E. The piece was 
then held in a two- jawed chuck, and this hole was enlarged and 
bored to the shape shown, so that the piece A would just fit it. 




FIG. 44. 



The jig was then put in its place in the tail-spindle and the 
drill-hole G was drilled. The swinging yoke H was got out by 
forging a piece of steel, machining it to the shape shown, and 
fastening by pins 1 to two flat sides milled on the body of the 
jig ; a knurled head-screw J secured the work. A portion of the 



INTERCHANGEABLE MANUFACTURING. 67 

face of the jig was milled away at K for clearance for the yoke 
H t to allow it to swing off and on freely. 

When in use the jig was set in the tail-spindle and the drill 
was held by a small chuck in the live spindle. The yoke H was 
swung downward and the work to be drilled was placed in the 
jig at F, as shown. The yoke was then swung up and the fast- 




FIG. 45. 

ening screw J tightened. The tail-stock was then run out, and 
the drill entering the hole G, the hole a was drilled. The hole 
E through the body of the jig allowed an easy escape for the 
dirt and chips. 

In Fig. 46 we have another adaptation of this style of drill- 
jig, although the construction is somewhat different. It is used 
for drilling the hole B B in the screw-plug C. These plugs 
were brass castings and were finished all over to the shape 
shown in section. The jig for the holes B B consisted of a 
piece of 1^-iuch round machine steel turned with a taper- 
shank to fit the tail stock the same as the other. It was then 
put into the live spindle and a hole P drilled to E by using an 
extra long drill of the diameter required. The front of the hole 
P was nicely rounded with a hand tool to allow an easy entrance 
for the drill when the jig was in use. The jig was transferred to 
the milling -machine and a section was milled away at M M to the 
depth shown, so that the centre of the flange of the work C, when 
in position, would be in line with the drill-hole P. A machine- 
steel disk N was finished in diameter to fit the hole in the work 
C. A hole was let through the centre of this disk, and it was 
fastened by the screw on the flat milled surface of the jig, cen- 
tral and in line with the drill-hole P. The spring-pin Q was 
made with a spiral spring R at the back and a handle at S, a 
clearance-channel T being cut in, thus allowing the pin Q to be 
pulled back and the work released. When in use the work C 



68 



TOOL-MAKING AND 



was located on the jig by the disk N. The tail-spindle was run 
out and the first hole B in the flange was drilled to the depth 
required. The work was then turned around the disk N until 
the hole drilled in the flange was opposite the locating-pin Q, 
which snapped into it by the tension of the spring E. The sec- 
ond hole in the flange was then drilled. 

The two jigs here shown for use in the speed-lathe are about 
the least expensive that could be devised for the drilling of the 
work shown, and it was surprising the amount of work that 




FIG. 



could be turned out with them. Jigs of this design and con- 
struction are very popular in the brass shop's, where the speed 
lathe is often adopted for work that is ordinarily done in drill- 
presses. 



A DEILL-JIG FOE ACETTLEXE GAS BUKXEKS. 

The work to be drilled was a solid casting of composition of 
the shape shown in Fig. 47, which had been dropped in a forni- 
ing-die under the drop-hammer and then run through a trimming- 
die to have each of the same shape and size. After the hole R, 
Fig. 47, had been drilled and tapped in the monitor, the piece 
was ready for the jig. This is shown from the side and front in 
Figs. 48 and 49. N P and Q, Fig. 47, are the holes to be 



INTERCHANGEABLE MANUFACTURING. 



69 



drilled ill the burner. and N were drilled to No. 17, and P 
and Q to No. 40 drill -gauge size. The small holes were after- 





FIG. 48. 



ward soldered at the top, thereby leaving two clear passages for 
the gas. 

The jig itself was a casting, flat at the back, with three pro- 
jections one at the top to hold the bushings, and two, L and J/, 
at the base ; also the two lugs L L. In the first place, a piece of 
T 5 -inch thick flat machine steel was planed square to fit the 




FIG. 4.9. 



inside of the burner and act as a gauge-plate to locate and 
hold it. It was then fastened with the central screw and the 
two dowel-pins F F, which were two Stub steel pins filed on the 



70 



TOOL-MAKING AND 



inside of each so that the burner would drop freely, but without 
play, between them. Kext a taper hole was drilled through the 
two lugs E E and the lock-pin D fitted in, with the side bearing 
on the work flat. The work B was then put in place and the 
lock -pin D driven in, thereby holding the work fast and snug. 
The bushings H I J and K were then made, hardened, and 
lapped to size. The holes for the bushings were then laid out, 
drilled and reamed to size, and the bushings driven in. The 
drilling was done in a two-spindle drill. First, the jig was stood 
up on the base M and the holes and P drilled, then 011 the base 
L and the holes J^and Q drilled; then, taking out the lock-pin 
D, the work was easily removed. The jig worked very satisfac- 
torily, each boy drilling from 250 to 1,050 a day. The casting 
was sunk in at G to give clearance to the work at B. 

DKILLIXG-JIGS FOE ODD-SHAPED CASTINGS. 

The two jigs shown in two views each, in Figs. 50, 51, and 
52 respectively, were used for the rapid drilling of the holes in 
the castings Figs. 53 and 54, and, as they proved rapid and accu- 

L v S L 




FIG. 50. 



rate producers, the design and construction of them may prove of 
interest to those having a number of holes to drill in odd -shaped 
castings. 

The first jig, Fig. 50, for drilling the casting Fig. 53, is a 



INTERCHANGEABLE MANUFACTURING. 



71 



very simple and inexpensive type, so constructed as to allow of 
the rapid locating and fastening of the work and the removal of 
the same when finished. The casting as drilled is shown in two 
views in Fig. 53, and has two holes A B drilled in each of the 





FIG. 51. 



FIG. 52. 



eight arms. Before being drilled the castings are chucked in the 
turret-lathe, and the centre hole C is bored and reamed to size, 
and the hubs are faced. 

The jig Fig. 50 consists of two castings, of which J is the 
body casting and T the lid. There were openings at all sides 
for the escape of the dirt and drillings. The legs L on four sides 
and those at M M on back are finished and scraped, so as to be 
dead square with each other. The face of the body casting is 
also squared with the sides, so that the lid will rest squarely on 
it. Two doY^el-pins U J71ocate the lid, and the thumb-nuts V 
V are for fastening it. A stud of tool steel, which is threaded at 
both ends and its largest diameter finished to fit snugly the cen- 
tre hole C, is let into the bottom of the body casting, as shown at 
0, and held rigidly in position by a nut P at the back. A large 
hole is bored in the -centre of the lid, so as to clear the nut Q. 
The sideway locating-poiut is at R. It consists of a Stub steel 
pin, which is hardened and driven into the body of the jig. The 
set- screw 8 is also hardened and let in through the projecting 



72 



TOOL-MAKING AND 



lug, and is used for forcing the work against the locating- 
pin R. 

The four bushings X are let in as shown, and the manner of 
locating and finishing thje holes was as follows: The body casting 
was strapped to the table of the universal milling-machine, and 




FIG. 53. 



the centre of each hole was located, and the hole was finished in 
turn by the use of a Brown & Sharpe height-gauge for locating, 
measuring from one side of the jig and from the miller- table, and 
using a sharp end, mill for finishing, first drilling the hole with a 
drill about ^-inch under size. 

The four holes for the bushing TFwere located by the "but- 
ton method," as described in Chapter III. After being located, 
the four holes were drilled and finished to size by strapping the 
lid on the lathe face-plate and locating each button to run true 
by the use of an indicator. 

When using the jig, the lid T was removed by unscrewing the 
thumb-nuts F, and the casting to be drilled was located on the 
centering -stud 0, the faced hub of the work resting squarely on 
the finished boss N. One of the angular-faced projections of the 
work is then forced against the locating-pin E by tightening the 
set-screw S. The nut Q is then fastened securely within the jig, 
as shown by the dotted lines in the plan view of the jig. The 
holes B in the projections are then drilled through the bushings 
X, that is, through every other one of the projections, by stand- 
ing the jig on each of the four pairs of legs L in turn. The jig 
is then rested on the legs M and four of the holes A are drilled 



INTERCHANGEABLE MANUFACTURING. 73 

through the bushings W. The lid of the jig is then removed, 
and the nut W and the set-screw 8 loosened. The work is then 
moved and located so that the holes A and B in each of the four 
remaining projections may be drilled. The operations of locat- 
ing and fastening the work and then of drilling; the holes are 
repeated. 

As can easily be seen, the design and construction of this jig 
is of the simplest possible character consistent with accurate and 
rapid production. Although it is necessary to locate the casting 
twice, the time entailed amounts to very little, and is fully com- 
pensated for when the simplicity and cheapness of the jig are 
considered, as in order to drill all the holes in one operation a 
far more complicated jig would have been necessary. 

In Figs. 51-52 are shown views of a jig of a rather more elabo- 
ate and complicated design than the first. It is used for drilling 
the holes in the casting Fig. 53, and finishing the hubs that is, 
the three holes G and the hole through each of the lugs F, the hole 
through the hubs at I and the finishing of the hub at H. As 
shown in the two views of the jig, the work is located at three 
points at each of the finished projections or lugs J, locating 
within the parts D, which are drilled to size in a preceding oper- 




FIG. 54. 

ation. The work is located side wise against the two adjustable 
stops K, by tightening the two set -screws Q against the work. 
The lid E of the jig is hinged within the body casting at F by 
the pin G. Legs are cast on two sides and on the bottom of the 
body casting, as shown at B and C respectively. The four 



74 TOOL-MAKING AND 

bushings L are for drilling the holes through the lugs F, and 
those at If, in the lid, for drilling the three holes G. The method 
used for fastening the lid while the work is being drilled is 
by means of a swinging -stud and a nut and washer J, the stud 
being hinged to swing free in the body casting at H, a slot being 
let in ifc and in the lid for that purpose. Two set-screws P are 
let into the lid for locating and fastening the work within the jig. 

The two large bushings 0, for use when finishing the hubs, are 
permanently located within the lid, while those for drilling the 
hole I in the hubs are inserted within them when in use. When 
using the jig the work is located and fastened within by the set- 
screws Q and P, and all the holes are then drilled. The two 
bushings JV are then removed, and the hubs are faced and re- 
duced to size. The fastening set-screws are then released, the 
swinging-stud I is thrown back, and the lid raised, after which 
the work is removed. 

All the various parts of both these jigs, including the cast- 
ings, are made sufficiently heavy and strong to withstand all 
strain to which they may be subjected when in use. The man- 
ner of locating the work is such as to be positive, and without the 
possibility of shifting during the operation of the tools. The 
means and points chosen for the fastening of the work within the 
jigs are such as to be rapid to manipulate, and in no way to in- 
terfere with the drilling ; and, lastly, the design and construction 
of both jigs are such as to dispense with all unnecessary parts 
and labor. 



JIG FOR DRILLING BOUGH CASTINGS IK PAIES. 

Fig. 56 shows two views of a drill- jig, with work in position 
for drilling holes in the tops of rough pairs of bracket castings. 
These castings were used in large numbers and were of the shape 
shown in Fig. 55. The three holes in the body portion were 
cored, and, as the pairs were not machined at any point before 
drilling, the holes were used as locating-points in the jig. The 
jig consists of a body casting in the shape of an inverted "T," 
X being the base and G the upright which supports the plate E 
and the work. The work is located in pairs on either side of the 



INTERCHANGEABLE MANUFACTURING. 



75 



upright by the dowel-pins D D I), which enter the cored holes 
and are held by the clamping device, a cross-.section of which is 



shown in Fig. 



This clamp is of tool steel, with wings at 




o 







FIG. 55. 



and J to swing over and clanip the work, the centre portion L 
being turned to fit the semi-circular bottom of the slot in the 
upright G. A plate H is let into and fastened to the front of the 
upright G by the two screws N N. This plate has a stud M fast- 
ened in the centre of it, in line with the circular portion L of the 
swivel-clamp. The face of the stud is finished to the same 
radius as the portion L and is of a length sufficient to allow of the 
face acting as a back bearing for the swivel -clamp to swing on. 




FIG. 50. 



This construction allowed of making the clamp in one piece, and 
gave better results than if one of the wings had been made sepa- 
rate. About -gV clearance was given lengthwise to the circu- 




76 % TOOL-MAKING AND 

lar portion L for rapid fastening and releasing when in oper- 
ation. The plate E serves as bushing-plate and bushings 
as well. It is of tool steel, with three holes at each side as 
guides when drilling the holes A A A. The holes C C C are 
countersunk to allow a ready entrance for the drill. The plate 
is hardened and drawn slightly, after which it is ground on both 
sides and the holes lapped. The plate is 
located on the body casting by two flat- 
head screws F and two dowel -pins not 
shown. 

When the jig is in use the clamping de- 
vice is swung out of the way and a pair of 
castings are located 011 the jig, dowel-pins 
D D I) being made an easy fit in the cored holes. The swivel- 
clamp is then swung back and the screw K is tightened against 
the castings, thus fastening the work against the sides of the 
upright G. The six holes are then drilled. This jig allows of the 
drilling being accomplished to the required degree of accuracy 
and iuterchangeability and in a very rapid manner. The swivel- 
clamp, for fastening the casting against the rib sides, can be 
adopted to advantage for locating and fastening work of a vari- 
ety of different shapes, whether the parts are sent to the jig 
rough or are first machined at different points. 

JIG FOE DRILLING AND COUNTERSINKING. 

The jig shown in Figs. 59-60 was used for drilling and counter- 
sinking the holes D in the casting Fig. 58. The castings before 
being drilled are bored at A to a diameter of 1 J inches, and 
the hub is faced at b ~b. The hole D is required to be central 
with the rib C. The parts comprised in the jig are: the body 
casting, with the circular portion at E, a base at P, and two 
feet at E E\ the bushing R G and the locating and fastening 
device J I L K and N. The portion E is bored at the front 
slightly larger than the hub of the work, and is faced at the back 
for the nut N. The bushing G is hardened and ground and 
forced into the top. It is lapped to fit a combination drill and 
countersink. The locating and fastening device consists of a 



INTERCHANGEABLE MANUFACTURING. 



77 



machine-steel stud with the nut N, and is turned at K to fit a 
reamed hole at E, and at F to fit the bored hole in the casting. 




FIG. 58. 



A half-round groove is let in at L as clearance for the drill. A 
large head at J and a washer J with a section cut out at. M M 
complete it. The work is located on the jig, so that the hole 
when drilled will be central with the rib C by entering the rib 





FIG. 59. 



FIG. 60 



into the slot at 0. A slot is let in at Q in the base as clearance 
for the end of the work. 

When in use the washer I is slipped off the locating-stud and 



78 TOOL-MAKING AND 

a casting is located. The washer is then slipped over the neck 
of the stud and the nut N tightened. The hole D in the work is 
next drilled and countersunk. To remove the work all that is 
required is to loosen the nut N and slip off the washer. 

A JIG FOE DKILLING CAMS. 

The earns to be drilled, Fig. 61, were of brass, ^--inch 
thick, cut from a bar of 1-inch round stock, the cutting off 
being done in the monitor. They were to be drilled eccen- 
trically, as shown, with a |^-inch drill. Of course, to drill a 
hole of this size in pieces so small and have all approximately 
alike necessitated a jig that would hold them correctly and 
securely. The jig is shown in Fig. 62, with a top and an end 
view, the top view with the plate for holding the bushing off. 
Fig. 63 shows plate and bushing. 

A casting was used for the jig proper, with two wings as 
shown, so that it could be set true and strapped on the drill-table. 
The bushing-plate was planed on the top and bottom and fastened 
with four flat-head screws J and two dowel -pins K. A bushing 
L, of tool -steel, with an -J-J-inch hole, was then made, hard- 
ened, ground, and lapped. The casting, with the plate in posi- 
tion, was then set on the face-plate of the lathe, and a hole |- 
iuch in. diameter bored straight through at E. The hole in the 

plate was then bored out so that the 
bushing would just drive in. The plate 
was then removed without disturbing 
the casting, and a piece of turned steel 
\l -inch in diameter, with a prickpunch 
mark exactly ^-inch from the centre, 

driven into the hole E in the casting tight enough to keep it 
from turning. The casting was then moved sidewise on the 
face-plate until the prickpuuch ran true. The piece of steel 
was then removed and the hole E rebored to 1 inch in diam- 
eter and ^-incli full, deep; that is, so that the work, Fig. 
61, would enter freely. The casting was then removed from 
the lathe and a slot planed in the way shown at N, Fig. 62 ; 
that is, 1-J inches wide at the front and running into the 




INTERCHANGEABLE MANUFACTURING. 



79 



hole B as shown. A piece of steel, C, -&-inch thick, worked 
out in the way shown to keep the work from being bruised, 
was then made. A y^-inch taper hole was drilled in A to 
admit the lock -pin D, which was of Stub steel, with one flat 




FIG. 62. 

side facing the work. The lock-pin and the piece C were both 
hardened. G is a bracket of sheet steel cut out and bent in 
the way shown and held by screws II; Fis the knock-out pin, 
//the spiral spring, and this completed the jig. The plate, Fig. 
63, was screwed on and the jig strapped to the drill-table. The 
work, Fig. 61, was dropped in place, also the piece (7, and the 
lock-pin D was given a tap, which held the work fast. The hole 
was drilled, the lock-pin removed, and the knock-out hit sharply 



80 



TOOL-MAKING. 



with a hammer, causing the work and piece E to come out 
without any trouble, the spring H bringing the knock-out back 
in position. 

One thing necessary was to have the hole E in the casting and 
the hole in the bushing exactly the same size as the drill ; also 
the drill ground central, thereby leav- 
ing only a very slight burr, as, had it 
been otherwise, it would have caused 
trouble in removing the work. 

The jigs illustrated and described 
in this chapter should prove suggestive 
for the devising of means for the rapid 
and accurate production of different 
shaped repetition parts which are to be 
drilled. One thing which should al- 
ways be kept in mind when designing 
or constructing fixtures for interchange- 
able production is this: the fixtures used for rough or simple 
shaped castings should, if anything, produce quicker and cheaper 
than those for machined or perfectly interchangeable ones, be- 
cause castings of the first type are, as a rule, sold at such a 
low cost that unless they are produced very rapidly no profit is 
possible. 




J, 



FIG. 63. 



* 



CHAPTER V. 

Intricate and Positive Drilling-Jigs. 

As we are now about to take up descriptions of a class of 
drilling- jigs in which the utmost accuracy and interchangeability 
in the product are essential, I wish to impress upon the mind of 
the reader the necessity of making himself familiar with the fun- 
damental principles and the most accurate and practicable means 
for accomplishing accurate results in the finishing of the various 
parts of such jigs. For this reason I call his attention again to 
Chapter III. , in which is contained all that will help the mechanic 
to devise and construct accurate drilling- jigs successfully. 



JIG FOE DRILLING A MULTIPLE-CAM BODY. 

In Fig. 64 is shown a casting with two circles of holes drilled 
in face at A and B in the relative positions shown in the pro- 
jecting lugs. As this casting, when finished, formed a part of 
an attachment for an embroidery sewing-machine, and acted as a 
multiple cam, the accuracy of the 
holes had to be positive. The jig 
used for drilling them is shown 
in two views in Figs. 65 and 66, 
and as the design and construc- 
tion are clearly shown, very little 
description is necessary. We will 
confine ourselves, therefore, to the 
accurate locating and drilling of 
the work. D, Fig. 65, is the 

body casting, finished on all sides, as shown, the lid L being 
hinged on one end, at M. It is then swung on the lathe face- 
plate and a hole is bored through both, at Q and E respec- 
tively. The hole E is to admit the iudexing-plate stem G, and 
6 81 




FIG. 64. 




82 



TOOL-MAKING AND 



the hole in the lid is for clearance for the clamping-stud U"and 
also as a general point for finishing the bushing-holes. The in- 
dex-plate is a forging ; the plate F is of tool steel, and the stems 
H and G of mild steel. The stem H is finished to fit snugly the 
centre hole in the casting Fig. 64, and is tapped for the clanip- 
iug-stud U. The stem G fits the hole in the base at E, and is 
shouldered and threaded for the washer I and nut J. The plate 
proper F is indexed to six and is hardened ; then it is ground and 
the notches lapped to a gauge, so that the divisions are spaced to 
the utmost accuracy. As a positive locator for the work the best 
point is the key way at C, Fig. 64 ; but before letting in the key 
in the stem H of the index-plate, Fig. 65, the bushing-holes in 
the lid L are finished. 

For this operation an arbor is turned up one end tapering to 
fit the driving-head of the universal milling-machine, and the 
other a driving fit within the hole Q in the lid. The lid is then 
forced onto it and the arbor driven into the head, which is set on 
the extension plate facing the spindle. A small centre drill is 
first used and the table set to allow of centring the holes on the 




FIG. 65. 

proper radius. Three holes, T, Fig. 65, are now drilled, and 
then finished to size by butt-mill with a sharp end cut. The 
three outside holes S are finished in the same way, and located in 
the proper relation to the first circle by using a standard plug, 
entering it into one of the holes T and then using the verniers 



INTERCHANGEABLE MANUFACTURING. 



83 



to get the exact distance from it to the side of the end-mill. 
When the bushings are finished and driven into the holes, one of 
the castings is clamped into the jig, and the index-pin TFlet into 
"the base of the jig at D is let into one of the index notches. 




FIG. 66. 

The casting is then adjusted until the holes when drilled come in 
the position shown in Fig. 64. The keyway is next located in 
the stem If and the casting removed. After the key is let in the 
jig is complete. 

In using this jig the work is clamped in position, as shown, 
and the -holes drilled through the bushings S T S T, which are 
directly opposite one another. The index-plate is then moved 
one space ; the first two holes drilled are reamed through the two 
extra bushings T and $, and four more holes are drilled through 
the other bushings, as before. The principle of this jig can be 
used to the best advantage for work in which holes are to be 
drilled around an exact radius. 



DBILLING- AND HUB-FACING JIG. 

Figs. 68 and 69 show two views of jig for drilling the holes 
F F F and E and facing the hub D of the casting, Fig. 67. It is 
very rapid in handling work, as well as accurate in production. 
It can be adopted for finishing work in which rapidity in drilling 
is the object sought, as one lever locks and positively locates the 
work in position. Before being drilled the casting, Fig. 67, is 
machined on the back A , the sides C C, and the channel B, thus 
allowing of positively locating it. The jig consists of one cast- 
ing, shown at G Gr G, which strengthens it for the locking-cam 



84 



TOOL-MAKING AND 



K. The work is located on the two spots H H on the bottom, 
and on the sides on the adjustable screws J J, while endwise the 
flat piece I locates it by the channel. The three bushings P P P 




are let in by the "button" method described in Chapter III, as 
is also the hole for the facing -bushing N t while the bushing for 
the hole E, Fig. 67, is ground to fit the inside of bushing H. 

The clamping- and locating-cam K M and L is made so that 
the portion K will press down the work on the spots H If and 
carry it against the plate J; while the portion L is finished to a 
slight pitch on the inner face as shown at 8, Fig. 70 which 
forces it against the screws J J. When in use the work is 




FIG. 



clamped within the jig, as in Fig. 68, by pulling down on the 
lever M of the locking-cam. The bushing is then removed 
and the hub D, Fig. 67, is faced. The bushing D is next in- 
serted, and the hole E and also the three others are drilled 



INTERCHANGEABLE MANUFACTURING. 



85 



through the bushings P P P. The locking-cam is thrown back 
and the work removed and another piece inserted. 

The locating and fastening of work within jigs by the cam- 




FIG. 69. 



lock here described is one of the most rapid and reliable means 
for accomplishing it, and can be adopted for the drilling of a 





large number of different -shaped castings where two or more 
portions have been machined, so as to get the work at the locat- 
ing-points to a uniform size. 



AN INTEICATE JIG FOE TYPEWEITEE BASES. 

As a practical illustration of an intricate jig and the locating 
and finishing of a large number of holes to the maximum of ac- 
curacy, the jig illustrated iu three views in Figs. 72, 73, and 74 
will serve as an example. It is used for drilling all the holes 
to the number of fifty-six in the casting Fig. 71. The casting 



86 



TOOL-MAKING AND 



when finished forms the base of a typewriter and must be abso- 
lutely interchangeable. 

In work of this kind care should be taken to have all the cast- 
ings of uniform size and shape. To accomplish this the pattern 
should be perfect and, in all cases of metal, finished at all points 
to the size required allowing, of course, for shrinkage and sur- 
plus stock at all the points to be machined. When perfect pat- 
terns are made there is no doubt of the result in the castings. 
The casting, Fig. 71, is first faced on all projecting lugs and sur- 
faces, to gauge, on a profiling fixture. The design and construc- 
tion of the jig are clearly indicated in the three views, and the 
finishing of all parts in any way similar to those used on the other 




jigs is accomplished in the same way. The points of sufficient 
interest to describe in detail are the manner of locating the work, 
the finishing of the bushing-holes and the clamping devices. 

The casting rests within the jig on the four legs A A A A, 
Fig. 71. It is located endwise against the two points Y Y, Fig. 
72 (these points being milled to the radius of the ends of the 
casting which locates in them), and sidewise by two adjustable 
set- screws B B., The clamping devices are all located on the lid 
M and consist of the three knurled head-screws A A A, Fig. 72, 
and of the cam-locks Z Z. These locks, shown clearly in Fig. 
75, consist of an eccentric turned stud and a square nut, both of 
which are hardened and located on the jig as shown. By giving 
them a half turn they force the work against the locating-points 



INTERCHANGEABLE MANUFACTURING. 



87 



Y T and also against the set-screws B B, and lock securely in 
position. The lid is located on the body of the jig by the three 
dowel-pins N N N, and clamped by the two swinging-clamps 



F N F 




FIG. 72. 



and the large knurled nut P. This manner of fastening con- 
tributes to the rapid locating and removal of the lid. The legs 
are on three sides of the jig and on the bottom. They are of 




FIG. 73. 



tool steel, hardened and lapped in the way before described. In 
finishing these legs a number of tool-makers mill a square at the 
top rather an elaborate way ; all that is necessary is to mill a 



88 



TOOL-MAKING AND 



slight flat on two sides, which answers all the requirements and 
is far more expedient. 

The most difficult part of the construction is the finishing of 
the bushing-holes. By reverting to Fig. 72 it will be seen that 

O P o 




FIG. 74. 

there are four sets of holes, at E 8 T and U, each set on a 
radius central with the centre hole Q. The first hole is that for 
the bushing Q, which is finished on the lathe face-plate by the 
" button " method. This hole is bored to a size really larger than 
necessary, so as to admit an arbor which is located in the divid- 
ing head of the miller. This being done with the head facing 
the spindle, the first set of holes E are centred and finished in 
the position shown by setting the table and head so that the cen- 
tre drill is on the proper radius with centre hole Q, and then in- 
dexing for sixteen, finishing six holes E and skipping 
the centre one. The next row 8 and the rows T and 
U are finished in the same way by lowering the table 
until the centre drill is on the radius required, and 
then indexing for twenty-five and finishing eleven 
holes on the arc as shown. The lid is then removed 
and the four holes V V V V located with buttons, 
inserting a standard plug in the holes Q and getting 
the distances from it and the side of the jig with a 
height-gauge, finally finishing the holes in the lathe. 
The holes WWW and X X, and also those in the 
side of the jig at E E E E and F F, all go through the same 
operation. The manner of locating and clamping the work 
in position and then drilling all the holes is clearly shown 




FIG. 75. 



INTERCHANGEABLE MANUFACTURING. 89 

in the three views of the jig and requires no further de- 
scriptio*n. 

The design and construction of the three separate and distinct 
types of jigs shown and described in the foregoing comprise the 
best principles for the positive locating, fastening, and rapid 
handling of work of the class shown, while the method described 
for finishing the bushing-holes is the most accurate that has yet 
been devised for accomplishing this part of the work. If fol- 
lowed out as defined, the results obtained will be satisfactory 
to all concerned. 



TWO DEILLLN T G-JIGS FOE SMALL, ACCUEATE WOEK. 

In Fig. 77 is shown a drilling -jig embodying a number of 
practical ideas. This jig is for spacing off and centring holes 
or punch-seats in small wheels, which are in turn used when sup- 
plied with punches for perforating leather shoe tips, and miscel- 
laneous service of that character. The wheel before drilling is 
shown in a cross-section at W, Fig. 76 ; and as finished, with all 
holes drilled and counterbored and the punches inserted, at H, 




FIG. 76. 



Figs. 79 and 80, in which is shown the machine on which the 
wheels are used. These wheels are of cold-rolled machine steel 
and are finished all over in the turret-lathe. 

As the holes or seats for the perforating punches are usually 
very small, it is not possible to drill them to the required degree 
of accuracy in one jig ; so two jigs were used one for spacing, 
locating, and countering the holes, and the other for drilling and 
counterboring them. The jig for spacing and centring the 



THE 

UNIVERSITY 



90 



TOOL-MAKING AND 



holes is shown in Fig. 77, and the jig for drilling and counter- 
boring in Fig. 76. 

The spacing and centring jig, Fig. 77, consists of a flat-bot- 
tomed casting A with two standards B B which support the in- 
dexing device. There is a shaft C with a wide shoulder at the 
front end to rest against the face of the standard, and an end pro- 
jecting from this shoulder to fit the hole in the wheel and threaded 
for the nut F. A small pin in the face of the shoulder locates 
the wheel in position on the spindle. The index-plate G has 




three circles of holes, the number of the holes being designed for 
handling as large a variety of wheels as possible. The index- 
pin J is located in a swinging arm II, which swings on a stud 
let into a corner of the back standard B. A flat spring K is 
fastened to the arm with the end resting in a notch in the index- 
pin. Instead of using bushings to guide the drills, a piece of 
y^-inch Stub steel is used, it being finished with a flat at L with 
three holes for the .drills. This end is hardened and the oppo- 
site end M is threaded for the adjusting-nut O located in the 
fork of the bracket N. This adjustment allows of marking dif- 
ferent combinations of holes in wheels of different thicknesses 
by the use of the one drill guide. 



INTERCHANGEABLE MANUFACTURING. 



91 



In conjunction with this drill-jig a small sensative drill is used, 
and as the design and construction are clearly shown a detailed 
description is unnecessary. The manner of using the jig, Fig. 




Gage- for Setting 
CounUrbore 



FIG. 78. 



77, is as follows: A wheel D is located 011 the spindle as shown, 
a drill is fastened within the chuck of the press, and the table A 
A of the press is set so that it can be raised just high enough to 
centre or spot the holes. The index-pin J is then set for the re- 
quired circle of holes by swinging and locating the arms H. 
After centring the first hole the next is located and centred by 
pulling out the index -pin J with the left hand and rotating index - 
plate G with the right, the outside of the plate being knurled to 
facilitate it. 

The jig for drilling and counterboring the wheels is shown in 




FIG. 79. 



FIG. 80. 



Fig. 76. It consists of a casting Q with a floating spindle S on 
which the wheels are placed to be drilled. This spindle is fin- 
ished on the front end the same as the one used in the first jig, 



92 TOOIj-MAKING AND 

the work being located and fastened upon it in the same man- 
ner, the locating-piu U entering the hole V in the wheel W. 
Two dowel-pins are let into extreme corners of the bottom of the 
jig to coincide with two holes drilled in the table of the drill- 
press, so located that the spindle S will be in line with the centre 
of the drill-chuck. By this means the holes can be drilled very 
rapidly and with the certainty that they will all point toward 
the common centre. When drilling the wheels, the spindle is 
rotated until one of the spotted centres is in line with the drill. 
The work is then pressed upward against it and the drill in- 
stantly locates it perfectly in line. 

The counterboring of the holes is accomplished in the same 
manner as the drilling ; the couuterbore being set to the required 
depth in the holes by means of the groove X, the table of the 




FIG. 81. 

press being raised until the face of the counterbore rests on the 
flat face Yof the gauge, which is slipped into the spindle holes of 
the jig. The table is then set, the gauge is removed, the work- 
spiudle 8 is reinserted and the holes in the wheel are finished to 
the diameter and depth required. 

The manner in which the wheels are used when finished is 
shown in Figs. 79 and 80. H is the wheel with the punches in- 
serted ; I is the piuking-cutter for pinking the edge of the work ; 
A the body of the machine ; B the cutter and disk spindle, which 
is rotated by hand by the crank handle F ' ; V a hard-rubber holder 
which runs free and can be adjusted on the yoke spindle T and 
raised or lowered by the knurled nut 0. A sample of the work 
produced is shown in Fig. 81. 

JIG FOR DRILLING AN ALUMINUM -BASE CASTING. 

Fig. 82 shows a base or stand of an electrical cloth-cutter, a 
casting of aluminum, 7^-inches long. There were eleven holes 
to be drilled around the outside. These were for 6-32 screws, 



INTERCHANGEABLE MANUFACTURING. 



93 



and were to hold iii place a sheet-steel shoe the size of the 
outside of the casting and the inside shown by the dotted line. 
There were also six holes drilled in the depressed part Z) which 




Casting to be drilled 



FIG. 82. 



were for 10-24 tap, and were to hold the standard that supported 
the cutter. Then there were three large holes 1^ inches in di- 
ameter by ^-inch deep, with a ^-inch hole in the centre, i-inch 




FIG. 83. 

deep. There were also four holes drilled within each of these 
large ones, for 4-40 screws. These holes were for plates which 
held rollers for the machine to travel on. 

The jigs used for drilling these holes are shown in Figs. 83 
and 85 respectively ; in all there were thirty -five holes, of which 



94 TOOL-MAKING AND 

twenty-three were drilled in the jig shown in Fig. 83. As will 
be seen, the jig is composed, of two main parts, the top and bot- 
tom. The bottom was a casting, for which a special pattern had 
been made, hollowed out on the inside to allow the work J to be 
set in, with clearance all around. There were lugs cast in each 
end to accommodate the swinging studs H H. After it had been 
planed flat on the bottom it was milled flat on the inside, and the 
gauge-plate K made and. fastened with screws and dowels. This 
plate was for locating the work, which had previously been 
milled out at that point to templet, as seen at D, Fig. 82. The 
top plate was then got out of cast-iron, planed on both sides 
and slotted on the ends for the lock-pins. The two were then 
strapped together, and the holes for the two dowel-pins I Jwere 
drilled and reamed. The pins were made and driven into the 
bottom piece F ; then using the centre of the gauge-plate K for a 
common centre, all the holes shown were carefully located by the 
button method, and then trued and bored in the lathe. 

Three holes were drilled in the position shown for the set- 
screws J J J. Next, the bushings were all made, hardened, 
ground and lapped to size, and driven home. The lock-studs 
H H were made of machine steel and the nuts or handles G G, 
also of machine steel, got out and put together, and 
the jig was complete. When using, the handles G 
G were given a turn so as to allow of their being 
swung clear of the plate E, which was then removed 
and the work inserted within the plate F, locating 
itself on the gauge-plate K. The plate E w r as then 
replaced, the lock-nuts G G swung back and tight- 
ened, and the three set-screws J J J also tightened. 
\Yhen all the small holes were drilled, the large 
j II j. I holes were drilled and counterbored by the com- 
F|G 84 bination drill and counterbore shown in Fig. 8-L 
N is a flat drill inserted within the counterbore ; L 
a screw for adjusting it, and J/a screw for holding it. 

This is the style of jig best adapted for this class of work. 
As will be seen, the work itself is of a shape hard to hold, and 
the way shown answered all requirements and could be relied 
upon to machine work that would interchange. 






INTERCHANGEABLE MANUFACTURING. 95 

Fig. 85 shows the jig for drilling the small holes within the 
large ones, for the roller-plate screws ; this itself needs little de- 
scription to be understood. As will be seen, it was composed of 
a flat piece of cold -rolled steel worked into the shape shown, and 
two disks turned up to just the size of the 
large holes in the base. They were then 
fastened one in each end, so as to inter- 
change in the large holes. The holes 
for the bushings were then laid out, FIG ^ 

drilled, and reamed; the bushings made, 

hardened, and inserted, and it was all ready. The jig was- 
placed so that the disks rested in two of the holes L L. The 
holes were drilled in each, and one end of the jig was swung 
over to hole A and the holes drilled in it. This proved a 
simple and reliable means of drilling these and getting them all 
alike, as they should be, as the roller-plates were blanked and 
the holes in them pierced in the press. 

The steel shoe mentioned in the beginning of this description, 
for the base, was blanked and pierced in the press. So the 
degree of accuracy necessary in the laying out of the holes can 
be easily seen when it is understood that they were to go on either 
way, and leave an equal margin projecting all around outside the 
edge of the castings. 



CHAPTER VI. 

The Design and Construction of Drilling-Jigs for 
Heavy Machine Parts, etc. 

CONSTEUCTING LAEGE DEILLING-JIGS. 

THE introduction of tools and fixtures for the production of 
duplicate parts of heavy machinery and tools has necessitated the 
devising of means and the designing of fixtures by the use of 
which the part, or parts, to be machined could be handled with 
ease and expedition. The result has been that where the proper 
design and construction of fixtures has been carried out, the fin- 
ished work has proved vastly superior to that done by the old 
methods. 

In designing and constructing drill -jigs for heavy parts there 
are a number of obstacles to be met and overcome, not found in 
jigs for the different classes of work shown and described in the 
preceding chapters. They are in effect as follows : In the in- 
creased size and strength of the jig castings. Then in the locat- 
ing- and fastening-points for the work, which must be so situated 
as to allow the work to be located and fastened within the jig 
quickly, with the least exertion on the part of the operator. 
Lastly in the locating and finishing of the drill bushing-holes, 
which cannot (as a rule) be successfully accomplished by the 
same means used in the construction of jigs for small parts. 

JIG FOE DEILLIXG A NAILING-MACHINE CEOSS- 

HEAD. 

The numerous and various jigs shown in the accompanying 
illustrations show clearly the most practical design and construc- 
tion for the various shaped castings shown. In Fig. 86 are three 
views of a cast-iron cross-head for a nailing -machine. This is 
finished at three points, at A A, B B, and the bottom C C. The 

96 



INTERCHANGEABLE MANUFACTURING. 



97 



holes drilled are eighteen in number ; four at each end at D ; four 
at E, and six at Fin the front projection. The jig for drilling 
them is shown clearly with the work fastened within it in the 
two views in Fig. 87. It consists of one casting with legs at each 




D 



end at G G. The work is located by forcing it endwise .against 
the two locators /and irrespectively, by the set-screws L L (see 
view, Fig. 88). Four straps, KKKK, fasten and hold down the 
work securely on two raised and finished spots in the bottom of 



QMOMQ 




FfG. 87. 

the jig. The bushing-holes are located and finished by the 
method described in the beginning of this chapter. When in use 
the work is fastened within the jig by slipping it down on the 
locatiug-points and tightening all screws and clamps. The jig is 

7 



98 



TOOL-MAKING AND 



then stood on end on the legs G G and the holes are drilled 
through the bushings Q Q, after which it is reversed and the 
holes in the opposite end drilled through the bushings P P. The 
large holes through the four projections are then finished by in- 
serting a boring- bar through the bushings and the cored holes 
in the four projecting lugs of the cross-head, in which four cut- 
ters are fastened, one end of the cutter- bar being fastened in the 
drill-press spindle, and the other end running in and passing 
through the hole in the centre of the table, as the bar is fed 
down. The jig is as simple as possible, and allows the work 
being very rapidly located, fastened, drilled, and removed. The 




IN 

s 



FIG. 88. 

projecting lugs on the sides for the straps or clamps K K K K 
strengthen the ends of the jig, and overcome the tendency to 
weakness in the projecting ends. The use of a boring-bar with 
four cutters for finishing the holes E, Fig. 86, is both economi- 
cal and productive of good results, saving time in the finishing 
of the holes and insuring their alignment with each other when 
finished. The use of the clamps for fastening the work tends to 
the rapid fastening and releasing of the same, as by a single turn 
of the nuts they can be swung on or off. 

DEILLING-JIG FOE OAST-IEON IMPEESSIOK EOLLEES. 

In the two views of the cast-iron impression roller in Figs. 89, 
90, we have a piece of work that would be difficult to handle with- 
out the use of a jig. The roller is turned and finished in the 



INTERCHANGEABLE MANUFACTURING. 



99 



lathe and then transferred to the miller and indexed for six, and 
the four channels T T T T are milled down its entire length. In 
each of these channels six holes, R, are drilled and in the plain 





FIG. 89. 



Fl<5. 90. 



side of the roller four counterbored holes, W, are let in. The 
inside of the roller is cored out as shown by the dotted lines, 
with cored vents at V V. A 2-inch hole through the ends at 
U ZJacts as a journal-bearing for a revolving shaft. The jig is 
clearly shown in the cross-sectional view in Fig. 91, and in the 
top and end views of Figs. 92, 93. X is the main casting, T the 
bushing -plate, and I the shaft on which the roller Z to be drilled 
is fastened. The locating-plate C revolves in the end B of the 
jig and projects through to the opposite side, the index-plate P 
being keyed to it at G and fastened by the nut H. The bush- 
ings N are for the six holes R in the channels, and those at M 
for the counterbored holes W W, Fig. 90. To locate the roller 
within the jig so that the channels in which the holes are drilled 
will be in line with the bushings, the locator D is used. It is 
fastened within a channel in C by the cap -screw shown, piece 




FIG. 91. 

J) fitting the channel E snugly, as shown in the cross-section ; 
while the roller is fastened to the shaft Jby the set-screws K. 

In the end view of the jig, Fig. 92, the iudexing-holes in the 
plate F are shown those for the holes in the channels are at 
R R R, and the one into which the index-pin J is entered, four 



100 



TOOL-MAKING AND 




in all. That for the counterbored holes is at <?. The top view 
of the jig shows the position in which the bushings N and M are 
locate^, and the manner of locating the bushing-plate by the four 
screws L and the two dowel-pins P P. By 
reverting to Fig. 91, the manipulation of the 
jig when in use, and the drilling of the work 
will be understood. The shaft I and the 
roller Z are inserted, fitting between the locat- 
ing-plate C and the finished hub on the end 
A, with the locator D in the first of the 
channels. The shaft I is then slipped through 
and set-screw K 1*1 the roller tightened. The 
jig is then set on the table of a large adjustable multiple 
spindle-drill; six of the spindles being set so that the drills 
will enter the six bushings N, and four of the remaining spin- 
dles so set that the counterbores will enter the bushings M. 
The jig is then fastened securely to the press table by cap-screws 
through the ends at C. The four holes W ( Fig. 84) are then 
counterbored, first removing the drills from the other six spin- 
dles. The counterbores are then removed, the six drills refast- 
ened to the spindles, and the index-plate revolved until the first 
channel in the work is under the bushing N. Index-pin J is now 
entered and the six holes drilled, when the index -plate is moved 
for, the next channel and the holes drilled in it, the holes in the 




M 



M 




FIG. 93. 



remaining two channels being drilled in the same manner. The 
use of this jig together with the multiple spindle-drill makes the 
handling and drilling of the heavy roller a simple operation, 
that would, however, be difficult to perform satisfactorily by 
any other means. Moreover, the work produced will be found 
to interchange perfectly. 



INTERCHANGEABLE MANUFACTURING. 



101 



DKILLING-JIG FOB DOVETAILED SLIDE-BE ACKETS. 

A separate and distinct type of jig for heavy work is shown 
in the three views in Figs. 94-95. It is nsed for drilling all the 
holes in the dovetailed slide-bracket shown in Figs. 96-97, and, 
as will at once be seen, can be located on the work simply and 




FIG. 95. 



rapidly. The bracket (Figs. 93, 97) has four holes drilled at 
V V V Fand two at W W. The four holes Fare for fastening 
the bracket to the body of the machine of which it forms a part, 
and those at W W for fastening a spindle-bearing to the portion 
on the bracket. The casting, before being drilled, is machined 
on the back at U, planed dovetailed at 8 S, and a cut is taken 
off the top at T T. The dovetailed surface is utilized as the 
positive locating-point for the jig, as it is shown secured in the 
work in the two views of Fig. 95. The bottom of the jig and 
the point Z are finished to coincide with the dovetailed surface 
of the work. The angular-faced clamp A is forced up against 
the work by the two set-screws B B and drawn up tight by the 
clamping-lever and stud C. The end locating-point is at I), 
which consists of a flat steel plate fastened to the overhanging 
end of the jig by two flat -head screws. The four bushings F F 
project down almost to the face of the jig, this being necessary, 
as the casting at this point is not machined. When being drilled, 
the casting rests on the back JTand the jig is located and fast- 



102 



TOOL-MAKING AND 



ened on it as shown in Fig. 95. The holes drilled, the jig is 
quickly removed by loosening the two set-screws B B and the 
clamping-lever C, which allows the clamp A to be slid back and 




U 

FIG. 96. 

the jig removed. The design of this jig gives a practical illus- 
tration of how simple and inexpensive tools for the drilling of 
heavy parts can be constructed, by choosing the most adaptable 
locating-points on the work, and designing the jig castings so as 
to have as few points as possible to machine. When locating 
and finishing the bushing-holes in this jig, it was first finished at 
all points necessary, and then clamped to the slide-bracket, or 
work, which was in turn clamped to the miller-table, with the 
top of the jig up. The holes were then located and finished by 
getting the distances from the machined sur- 
faces of the work and using the vertical at- 
tachment, thus doing away with the necessity 
of first laying out the holes on the work, then 
finding their location in the jig. This is a 
very good plan to follow when the shape of 
the jig castings will not allow of their easy fastening to the 
miller-table. Moreover, in getting the distances between the 
bushing-holes, the machined surfaces of the work are reliable 
points to measure from. 

DBILLING-JIG FOE POWEB-PBESS BOLSTEBS. 

Fig. 99 shows still another jig, in two views. It is for drill- 
ing all the holes in the press-bolster shown in Fig. 98. The cast- 
ing, as can be seen, is a rather difficult one to handle ; but by the 




INTERCHANGEABLE MANUFACTURING. 



103 



use of the jig the drilling is accomplished with ease and expedi- 
tion. The only finishing done on the casting before drilling, is 
to plane all sides of the two oblong projections, as shown at A A, 




FIG. 98. 



B B, and C C, to gauge. The holes drilled are the four D D D D 

and two E E, and one through each of the projections F F F F. 

The jig (Fig. 99) is in two parts, the lid and body casting. 



I / P U 

PLAN VIEW 




FIG. 99. 



There are legs on four sides and on the bottom. The casting to 
be drilled is located from the two oblong projections on the back, 



104 TOOL-MAKING AND 

as shown in the plan view, by the locating- spots C I and H and 
the set-screws K K and J) the large strap L holding it securely 
in the bottom of the jig. The lid is located by the two nuts O 0. 
The bushings N through each of the projecting lugs on the face 
of the lid, are for the holes through F F F F in the work. The 
four bushings R are for the holes D and those at Q Q for the 
holes E K When the jig is in use the work is located and fast- 
ened within it, as shown by the dotted lines in the plan view in 
Fig. 99. It is then rested on its back and all the holes in the 
face are drilled. The holes in the projecting lugs of the casting 
at .Fare drilled by standing the jig on each of its sides in turn 
and drilling down through the bushings N. In this jig the 
amount of time taken to locate, fasten, and then drill the work 
amounts to very little when the shape and bulk of the casting is 
considered. Jigs of this design can be used to the best advantage 
for the drilling of heavy castings on which are a number of pro- 
jecting lugs, and when holes are drilled in them to a given line, 
or in line with each other, as in the case of the casting drilled in 
this one. 

POINTS TO BE EEMEMBEEED. 

In constructing tools of the class described in this chapter a 
few things must be considered: first, to construct the tools as 
simple as possible and to make them positive, so that they can be 
handled by cheap help without the possibility of going wrong. 
Also, in choosing locating-points on the work for the jigs, take 
the same ones (wherever possible) for all succeeding operations, 
thereby eliminating, as far as possible, the margin of error 
which may be the result of preceding operations. For instance, 
let us consider the upper columns of drill-presses : The first oper- 
ation on such parts is the planing of the angular faces of the col- 
umns. These faces are then used as locating- and truing-points 
for the succeeding operations of milling and drilling. There- 
fore, if, when the columns were set upon the planer for the first 
operation, they were not set square with the ends, the error was 
overcome in the machining of the ends in the next operation. 
Another thing, tools of the kind shown should always be made 
as strong as possible, so as to withstand rough usage without in 



INTERCHANGEABLE MANUFACTURING. 105 

any way affecting their accuracy. If the tools are delicate, the 
time wasted in caring and looking after them offsets that saved 
in the machining of the work by their use. Also have a place 
for fixtures where they may be put out of the way when not in 
use ; do not have them encumbering the floor, as is all too fre- 
quently the case in a number of shops. This will tend to 
lengthen their life, and it will not be necessary to hunt all over 
the shop whenever they are wanted. 



CHAPTER VII. 

Drilling-Jigs of Novel Design and Construction. 

HAVING in preceding chapters fully described the most expe- 
dient means for accomplishing accurate results in designing and 
constructing the more familiar class of drill- jigs, as well as illus- 
trated numerous types, I will show in this chapter a number of 
jigs of special and novel designs and describe means for their 
proper making and rapid operation. 

DEILLING HOLES IN A SPIBAL LINE ABOUND A 

CYLINDEB. 

Fig. 100 shows two views of a jig used for drilling the holes 
A A and B B in the roller Fig. 101. As will be seen, the 
two sets of holes are drilled entirely around on a f -inch pitch 




FIG. 100. 



spiral, right and left respectively. When finished the rollers 
have hardened pins inserted in the holes, and act as cams for 

106 



INTERCHANGEABLE MANUFACTURING. 



107 




FIG. 101. 



moving small slides of an automatic machine. The jig, Fig. 
100, although simple in design and construction, is very accurate 
in production, and possesses some novel features seldom met with 
in drill -jig design. The jig consists of the body casting, of which 
A A are the legs, and B the bush- 
ing- and pin-plate. The roller 
to be drilled is fastened on the 
spindle D by the nut shown. 
This spindle moves freely in the 
casting at C. The right and 
left worms I and J are cut to a f -inch pitch, and are fastened 
to the spindle. The indexer K is of machine steel, indexed 
to twenty-six and fastened to the spindle by the set-screws 
L. The index-pin Q is fastened within the bracket P and is 
finished 011 the end to fit the index-notches in K, the spring R 
keeping it down tight. The worm-stud 0, of tool steel, is fin- 
ished to fit the worm snugly ; the head is knurled, and it is then 
hardened. The end of the spindle D, on which the work is fast- 
ened, is finished with a shoulder at E and two smaller ones at F 
F, the space between these two being reduced to a size sufficiently 
small to allow for clearance for the drill as it comes through 
the work. The drill-bushing T is let in the top B so that when 
the spindle projects to its furthest point the first hole drilled 
will be the exact distance required from the end of the work. 

When in use the work is fastened on the spindle and the index- 
pin 8 is placed in the first notch of the index-sleeve 7f, that is, in 
the position shown in Fig. 100. The first hole is then drilled. 
The pin is now entered into the next notch and the next hole 
drilled. And so on until complete circles of holes are drilled 
entirely around the work ; the stud O in the worm feeding the 
spindle-back as the holes are drilled. As the last one in the first 
circle of holes is drilled, the spindle is slid in by hand and the 
stud enters the worm J. The spindle is then revolved in the op- 
posite direction, and the other circle of holes drilled in the 
same manner as the first. The work is then removed, and the 
spindle fed back to the starting-point; another roller blank is 
fastened on the spindle, and the operations repeated as before. 
This jig can be adopted for the drilling of holes, on a given 



108 



TOOL-MAKING AND 



pitch, in circular pieces of work. Bushings to the number of 
circles required may be used. The one thing necessary is to have 
them spaced and located exactly the same distance apart ; which 
should be the same as the pitch of the worm. 

LNDEXING-DIAL JIG FOE DBILLI^G SMALL CAMS. 

Figs. 102-103 show three views of a jig in which the indexing- 
dial principle is utilized for the rapid drilling of the small cam, 
Fig. 104. This jig is so constructed as to allow the work when 
finished to be self-releasing. It consists of a body casting A 
planed and finished on all sides, and having legs B B scraped. 




FIG. 103. 




FIG. 102. 



FIG. 104. 



It is bored to admit the stem D of the index- and receiver-plate 
C, which has eight holes F bored and finished to allow of the 
work to be drilled fitting nicely within them, and thereby acting 
as receivers. The four holes L are the indexing- or spacing- 
points, and are all reamed to exactly the same size. The bush- 
ing-plate H is fastened by the dowel -pins //and the two cap- 
screws J J. This is done before locating and finishing the bush- 
ing-holes. The bushings K K are let into the plate II, as shown, 
and are ground and lapped to size. Care is necessary in the 
locating and finishing of the bushing-holes to get them in the exact 
position required, as it is necessary to have the holes in the cam 



INTERCHANGEABLE MANUFACTURING. 109 

eccentric to a given size. The index-pin P fits snugly in the 
hole in the plate M, and the holes L in the index- or receiving- 
plate. The spacing and locating of all holes for the bushings, 
index-pin, and receivers for the work are accurately accom- 
plished by the "button method" on the dividing-head of the 
universal milling-machine, in the manner described in a pre- 
ceding chapter. The receiver-holes F are all finished to size 
with a special reamer. 

When in operation one of the pieces to be drilled is placed in 
each of the eight holes or receivers F. The dial is then fed 
around until the first two places are under the bushings K K, 
when the index-pin P is entered into the hole L and the two 
pieces of work are drilled. The index-pin is now removed ; the 
dial revolved one space, and the index-pin re-entered. This 
brings the next two pieces under the bushings. The piece drilled 
drops through the jig at K ; the bottom of the jig being cut away 
at this point, as shown by the dotted lines. The second -piece 
drilled remains at G. Xow the dial is moved around and the 
empty receivers, are filled, as the finished work drops out. As will 
be readily seen, the design of this jig allows of the continuous 
drilling of the work, without loss of time in the removal of same 
when finished. Moreover, the placing of the work in the empty 
receivers can be accomplished very rapidly, which is one of the 
best features of the jig, as this part of the work is quite a factor 
in the rapid handling and production of small parts by drilling. 
This jig can be used to advantage for the drilling of holes in 
small parts which have been previously machined to a uniform 
size. For the drilling of work in which great accuracy in the 
product is desired the indexing- or spacing-holes in the dial 
should be equipped with hardened-steel bushings, which should 
be iapped to a size allowing of a snug fit for the index-pin, thus 
insuring the accurate locating of the work and the positive fast- 
enings of same while being drilled. 

JIGS WITH IKDEXIKG-PLATES. 

In the jigs shown in Figs. 106, 108, 109, respectively, we have 
two more adaptations of the indexiug-dial principle for a sepa- 
rate and distinct class of work. These possess features and at- 



110 



TOOL-MAKING AND 




FIG. 105. 



tachments which iu design and construction are not found in 
any of the jigs previously shown. That shown in Fig. 106 is 
used for drilling all the holes (except the centre one C) in the 

spider casting, Fig. 105 ; that is, those 
marked B and A, through the project- 
ing lugs. The design of this jig is 
clearly shown in three views, and the 
method of construction can be readily 
understood from the description of 
the others. When in use the casting, 
Fig. 105, is fastened on index-plate H t 
Fig. 106, by entering into the stud K, 
and then fastened by a nut at L. It 
is located against the small projecting piece 0. The index-pin V 
is then entered in one of the holes N by feeding the index-plate 
around the desired distance by worm C. The holes through one 
of the projecting lugs B, Fig. 105, are then drilled through bush- 
ing P. The jig is now stood on the legs B E E R, and one of the 
holes A is drilled through the bushing Q at the back. Index-pin 
U is pulled out, the dial fed around one space, and the next two 
holes are drilled. Index-pin U is equipped with a spring which 
keeps it tightly down 011 the plate. The nine holes M are clear- 
ance-holes for the drill, and are finished slightly larger than the 
hole in bushing Q. The index-plate H is a good fit between the 
front and back of the jig, to allow it to revolve freely without 
play on its face. The bearings for the worm-shaft are cast on 
the edge at B B. The main casting is cut away at E, as shown, 
in order to allow of the handle F revolving freely. 

This jig can be used for drilling a number of different sizes 
of castings of the same shape ; that is, with the number of pro- 
jections reduced or increased by changing the index-plate, or, 
better still, by finishing it with a number of different circles of 
holes. This will allow of indexing any number of holes in the 
casting to be drilled within its capacity or for the drilling of 
regularly spaced holes in castings of a circular or irregular 
shape. The use of the worm for revolving the index-plate, 
although not absolutely necessary, is far preferable whenever the 
quantity of work to be drilled will allow of the extra expense 



INTERCHANGEABLE MANUFACTURING. Ill 

to the usual way of revolving the plate by hand ; for by having a 
worm a fair fit in the hobbed rim of the index-plate, it contrib- 
utes to the strengthening and rigidity of the plate while the 
work is being drilled. 

In Figs. 108-109 we have the other adaptation of the dial 
principle, as used for the finishing of work in a manner entirely 
different from any other before shown. The piece machined in 




this jig is shown in Fig. 107. It is a drop-forging and is first 
machined at three points at the back at A A A on a milling fixt- 
ure. The centre hole S is bored and reamed to size, and the top 
C is faced in a special chuck in the turret-lathe. The remaining 



112 



TOOI^MAKING AND 



operations necessary to finish the piece are all accomplished by 
the use of the jig shown in plan and cross-sectional views : i.e., the 
drilling of the hole D, Fig. 107, in the centre of each end; 
the facing of the top ; the finishing of the parts E by a hollow 
mill ; the facing of the wide surface of shoulders F, and the fin- 
ishing of the half-round bearings G G. As this jig is of a novel 
and special design, a detailed description of the practical points 
necessary to its successful construction is essential. 

The body or base of the jig is of cast-iron, with a slot B at 
either end for clamping it to the drill-press table. The three 
raised surfaces E and F F locate the work. The lugs C C are 
the side locating-points, and those at I) D are for the set-screws 
H If. Base A is first planed on the bottom, and the projections 




FIG. 107. 



are finished to the height shown. It is now strapped on the 
lathe face-plate, and bored and threaded for the central locating- 
and fastening -stud, which is of tool steel, turned and finished to 
the shape shown. This stud is threaded at S to screw tightly 
into base A, and at E to fit the centre hole in the work 0, and 
is reduced for the rest of its length to the size shown at Q. 
Finally, the end C is threaded for the nut V. The locating-points 
C C are finished so that when the work is forced against them by 
the set-screws H H, it will be in the position shown in the plan 
view of Fig. 108. The dial or bushing-plate P is of cast-iron, 
finished all over, and bored and reamed in the centre to fit snugly 
the locating-stud Q. The holes for the six bushings 1 1 K K 
and J J are located and finished to the size required on the 
lathe face-plate, care being taken to get the centres of all six on 
the radius required, and to space them accurately. Next, the 



INTERCHANGEABLE MANUFACTURING. 



113 



bushings are made, hardened, ground, and lapped to size, and 
forced into their respective holes in the plate P. 

v Before locating the six indexing-holes L, one of the forgings, 
Fig. 107, was laid out and strapped on the lathe face-plate, and 




FIG. 108. 

the hole D at either end bored and reamed to size. This forging 
was then fastened within the jig, Fig. 109, and used for locat- 
ing the first index-hole in the following manner: Two steel 
plugs were turned to size, to fit the bushing / 1 and the holes 
D D, in the work. By inserting these plugs through the biish- 
iugs, the bushing-plate P was accurately located rigidly in posi- 
tion. The first index -hole was now drilled through the plate P 
and into the projection M of the base A. Next, the hole was 




SECTION ON XV 
FIG. 109. 



reamed with a taper reamer until the taper-locating or index-pin 
N entered to the depth shown by the dotted lines in the cross- 
section, Fig. 109. Bushing-plate P was then removed, and the 

8 



114 



TOOL-MAKING AND 



five remaining index-holes L located and reamed to size on the 
dividing-head of the universal milling-machine. All the parts 
were assembled, as shown in the two views, and the jig was com- 
plete and ready for work. 

For use the jig is bolted on the table of an adjustable multi- 
ple spindle-drill, and two of the spindles set so that the drills 
will enter the bushings II. The arms of the drill-press are 
adjusted to bring the spindles into proper line and are then 
clamped. The holes D D in the work, Fig. 107, are drilled, 
then the drills are removed, the nut V loosened, and the bushing- 
plate P is revolved one space. Index-pin N is now re-entered 
and nut V tightened, which brings the facing-bushings J J in 
line with the work. The top being then faced, the plate is re- 
volved one space and the bushings K are brought in line. Next, 
the lower shoulder of the work is faced and the bearings G G 
finished, after which the work is removed, another piece located, 




FIG. 110. 



and the operations repeated as before. As will be seen, the use 
of this jig insures the accurate finishing of the Avork and its per- 
fect inter changeability. Jigs of this design can be used to the 
best advantage on multiple spindle-drills. 



INTERCHANGEABLE MANUFACTURING. 



115 



DRILLING HOLES IN A SPIDER CASTING. 

Fig. 110 shows three views of a jig that is self-explanatory, 
and is merely illustrated to show how the drilling of a number of 
holes in a piece at a given angle to each other may be accurately 
accomplished in jigs of the simplest construction. The work, 
Fig. Ill, is fastened within the jig 
on the stud D as shown in Fig. 110, 
and located against the adjustable- 
screw I by set-screw K, which allows 
of the rapid locating and removal of 
the work. When the jig is in use 
the nut L is removed, the piece to 
be drilled slipped onto the stud and 

located on a raised flat surface on the inside. The jig being 
stood upon the first pair of legs C C, the first hole is drilled. 
It is then stood on the next pair of legs, and another hole drilled, 
and then the operation is repeated for the third hole. 

A DRILLING- AND TAPPING-JIG. 

The jig shown in Figs. 112, 113, and 114, was for drilling 
and tapping cast-iron hoods of the shape shown in Fig. 115. 
There are three bosses projecting from the hood, equal distances 




FIG. 111. 




FIG. 112. 



apart, and these bosses were to be drilled and tapped to f -inch, 
and it was necessary to have them accurately spaced. After 



116 



TOOL-MAKING AND 




FIG. 113. 



they were drilled and tapped, a f -inch tube was screwed on to 
each of the holes and the tubes were each reamed for a piston, 

the three pistons meeting in the 
centre, as shown in the bottom view 
of Fig. 115. The pistons were 
worked by an eccentric and formed 
a part of a motor. As will be seen, 
a piece of this shape was hard to 
handle and required reliable means 
for holding it. 

The main piece or frame of the 
jig was the casting B, well ribbed 
and strong, with a good, stiff base 

A. After the base was finished it was planed on the front, for the 
slide was of cast-iron, and was planed and fitted to slide nicely 
within B B. A hole M was then bored in the centre of C and 
tapped. Two gibs D Z> of machine steel were made and fastened 
with screws and dowels, and scraped until the slide C would slide 
freely. The locating-disk K of cast-iron was then made, as 
shown in Fig. 114. It was first bored in the centre for the shoulder- 
screw Nj and then turned and hollowed out to just the size of the 
rim of the hood, Fig. 115, leaving a wall all around. The back 
was faced off and relieved at O. After that it was set up in 
the miller and indexed accurately, locating and milling three 
F's at F. It was also indexed in thirds at P, to give clearance to 
the lugs of the casting. It was then fastened so as to revolve 




CM 



CD 



FIG. 114. 



freely, without play, on the face of the slide (7, turning on the 
shoulder-screw N. The spring-lock. G was then made and fast- 
ened to the side of C ; so that, when locked, one of the lugs of 
the work would be directly under the bushing Q. The project- 



INTERCHANGEABLE MANUFACTURING. 117 

ing piece of the bushing was fastened with screws and dowels, 
and the bushing driven in. The two studs 1 1 were turned and 
threaded at one end to screw on to the shoulder, 011 the face of 
C. They were then tapped out at the other end for the two 
screws shown. A hole was drilled and tapped in the centre for 
the lock -screw L. The parts were then all assembled and the 
hood placed within K, the three lugs fitting into the slots P. 
The locking-latch // was swung on, and the plate K moved 
around until the lock -pin G, which was equipped with a light 
spring, entered one of the F's. The lock-screw L was then 
tightened, and the work was held fast. The jig was clamped on 
the table of the two-spindle drill -press by a C-clamp at each end, 
and the hole drilled through the 
bushing into the work. The jig was 
then removed and a stud the size of 
the hole entered, through the bush- 
ing Q, into the hole in the work. 
A hole was then drilled at R and 
reamed taper through the slide C 
into the back at A, for a tool-steel 
pin, which, when inserted through 

the taper holes, located the work central with the bushing. The 
slide JVwas then slid over the other end of the jig, and, when 
central with the other spindle, it was held there and drilled and 
reamed for the hole R as before. 

The jig was now ready for work, and it was set upon the 
drill-press and the work inserted. The taper-pin was then put 
in place, and the first hole drilled ; then, on loosening the lock- 
screw L, the disk K was moved around to the next notch, the 
screw tightened, and the next hole drilled, and likewise with 
the other. The three holes being drilled, a tapping attachment 
was inserted in the other spindle, and we were ready to go ahead. 
The slide C was moved over, the taper-pin entered into R, and 
the tapping accomplished by operating the same as before. The 
hood was then finished and removed and another inserted. The 
jig was easy to handle and the work was accurately finished. 
The idea of drilling and tapping in one operation added to its 
usefulness and value. 




118 



TOOL-MAKING AND 



A NOVEL DEILL-JIG. 

The work to be drilled by the jig here shown was a piece of 
steel If inches long, with a -f -inch hole reamed through the cen- 
tre, and there were sixteen holes, 22 -drill-gauge, to be drilled 
as shown in Fig. 116; that is, entirely 
around on a |-inch pitch helix. Then 
there were three holes from A to B, Fig. 
116, so that when these were separated, as 
shown in Fig. 118, and finished on a milling 
rig, they would form two perfectly fitting 
cams, which, in a friction-clutch that we 
were making, would open and close by 
the aid of two fingers, not shown. Fig. 
117 shows the jig complete. 
A is the table of the drill-press ; B a clamp, showing how it 
was secured to the table ; C the body, which was of cast-iron, 
planed on the bottom, with a hole through it for the shaft E; 



Jlli'ilHUIII 



J 



FIG. U6. 




FIG. 117. 



D a piece of flat machine steel, 1 J inches wide by -f -inch thick, 
bent in the way shown and fastened to the body by two screws 
at G and the dowel-pins H. The index-plate J was a piece 
of machine steel 2^- inches in diameter, with sixteen grooves 




INTERCHANGEABLE MANUFACTURING. 119 

milled iii it to admit the lock-pin P, and to square the holes 
evenly. The worm I was of iron, cut on a f -inch pitch, with a 
cross-groove at 0. The pin R was driven into D and fitted 
smoothly the worm as shown. M was the lever for raising the 
lock-pin, and JV the spring to keep it in the groove in the index- 
plate. T was the piece to be drilled, the shaft E 
being turned to fit the J-iiich reamed hole, and the 
thread cut on the end for the nut 8 to keep the work 
in place for the drilling. F was the bushing, to fit No. 
22 drill. The index-plate was turned one space at a 

prp 118 

time and the pin R would, in the course of sixteen 
f-inch spaces, cause the worm Jto make one complete turn on the 
f -inch pitch, when the pin L would be in line with the first of 
the three holes K, and the pin R in line with the slot in the 
worm at 0. The pin L was then entered with the first hole, then 
the next by pulling the shaft out, and then the last, when it 
could be easily broken apart, the holes having all but run into 
each other. The worm and index-plate were secured by set- 
screws, as shown. 

Four different sizes of cams were made, f-inch, |-inch, 
1^-inch and 1^-inch, respectively; and all that was necessary 
to alter the jigs was to take off the worm and index-plate and 
replace with other sizes. 



CHAPTER VIII. 

Use of Milling-Machines for Modern Tool-Making, 

Interchangeable Manufacturing and 

Jobbing-Shop Work. 

THE UTILITY OF MILLING -MACHINES. 

THE development of precision machine tools to the present 
high state of efficiency is responsible more than anything else for 
the results which are now being attained in the making of tools 
and fixtures and devices for interchangeable manufacturing and 
the machining of repetition machine parts. The one machine 
tool which has contributed more than all others to the attainment 
of results in modern tool-making is the milling-machine plain, 
universal, and vertical. 

The utility of millers is by no means generally known. To 
a remarkable degree they are considered adapted only to tool- 
room uses or in making duplicate parts. As not every shop or 
factory has need for a strictly tool -making department, or turns 
out interchangeable work, investigation into the many uses for a 
miller in finishing ordinary, as well as special, work is not car- 
ried out as it should be. That they are capable, with attach- 
ments, of performing a wider range of work in jobbing-shops 
than perhaps any other machine tool, and at lower cost, is a fact 
that is now attracting the attention of progressive managers. 

A well-designed milling-machine, properly constructed, is 
to-day recognized as one of the most important tools in every 
well-equipped machine-shop. Many operations heretofore done 
on a planer or shaper are now done much more perfectly and 
economically on a milling-machine, and for this class of work 
the use of end- or surf ace -mills has recently come into general 
favor, as this form of mill will remove metal very rapidly and 

leave the surface in good condition. 

120 



INTERCHANGEABLE MANUFACTURING. 121 

The horizontal-spindle machines in the plain or universal 
forms are in general use and familiar to all ; and for many kinds 
of work, such as index- milling, or milling of any kind where 
work is carried on centres or held in head centre; making irreg- 
ular or form cuts requiring the use of a series of cutters held on 
arbor which may or may not be supported by outward-arm; 
slot-milling, and a variety of operations called for in every -day 
practice, these machines with spindle in horizontal position meet 
all the requirements and are most convenient and effective. 

Special machines, such as the Lincoln and modified types of 
this class, are in use for duplication of parts; but 'the two main 
types heretofore in use for general purposes have been the hori- 
zontal-spindle and the vertical -spindle machines, and, as stated, 
each of these classes have their decided points of superiority. 

While the milling-machine has no claim to antiquity, the 
manner in which it has been adapted and used for all classes of 
fine work, and the rapidity with which it is becoming understood, 
have more than compensated for its late birth. Although the 
youngest of the machine-tool brood, it is now the most univer- 
sally used one and can well be placed at the head of them all. 
The modern tool-room, where claims are laid to doing good work, 
that is not equipped with a universal milling-machine is to-day 
a paradox indeed. Still, notwithstanding the fact that nearly all 
shops have such machines, their use and manipulation are not 
generally understood ; that is, we mean that the large and wide 
range of work possible to machine on them is not appreciated 
by mechanics in general. 

When we state that the use and adaptation of the milling- 
machine are not understood as they should be, we do not refer to 
its use for the ordinary classes of work, but to special work such 
as jigs, tools, dies, and fixtures for the machining of repetition 
machine parts and also for economic manufacturing. 

As one writer in The American Machinist has aptly said: 
"Of all the machines to be found in the modern tool-room the 
universal-miller stands pre-eminent. This is the machine of 
applied geometry. The combinations and positions obtained by 
means of a first-class universal are almost endless. A jig-body 
properly set up in a universal may be rotated, swung, twisted 



122 TOOL-MAKING AND 

around, raised, lowered, moved laterally or crosswise, set to any 
angle, drilled, bored, reamed, faced, slotted, profiled, indexed, 
and in some cases completely machined and made ready for the 
bushings without changing the original setting. There is scarcely 
any problem in jig-making, no matter how intricate, that cannot 
be worked out on a universal with the greatest ease, and posi- 
tive distances, angles, and arcs in every direction are only a mat- 
ter of correctly reading the index-plates or wheels." 

IMPBOVEMENTS IK CONSTBUCTION. 

During the past few years great improvements have been 
made in the construction of universal milling -machines, so that 
now they are adaptable for a larger variety of work than ever. 
As incentives to the further improvements of such machines, 
their use has been largely extended and their advantages for cer- 
tain classes of work are becoming better understood. It is ap- 
parent that the constant aim of the designer has been to increase 
the range of universal milling -machines, and the result to-day is 
that they are used for a variety of work simply astonishing. The 
attainment of these results can directly be traced to specialization 
in manufacturing and to the employment of jigs, fixtures, and spe- 
cial appliances throughout in the production of the machines. 

UNIVEBSAL MILLING-MACHINES. 

It is not so long since that the universal milling -machine was 
looked upon as a machine useful only for tool work, and a first- 
class tool -maker the only man to handle it. In a sense it was 
looked upon as a luxury which only a few shops could enjoy. 
To-day all this has changed and, while the machine is used for a 
larger and better variety of tool work than ever, it is in the pro- 
duction of repetition parts that its great value has become ap- 
parent. Thus this tendency to the universal use of the machines 
has given more and better work to the skilled tool-maker ; for 
where large quantities of parts are to be milled, a special jig, 
fixture, or a device of some sort is, of course, necessary, in order 
that the cost of producing the parts may be reduced to the mini- 
mum. There are any variety of parts which can be rapidly and 
accurately machined by simple indexing or light-chucking de- 
vices on these machines ; and as the economy in the production 



INTERCHANGEABLE MANUFACTURING. 123 

of even a small number of parts machined by their use usually 
more than pays for the cost of the fixtures there is no good ex- 
cuse for their nou -adoption. 

To-day the proprietor of any machine, tool, or die manufac- 
turing establishment who wishes to do everything possible to as- 
sure success must see first that his tool -room equipment is as 
complete as the demands of his specialty necessitate. He should 
also start out to do this with the conviction that it will not prove 
merely an additional item of expense, but, on the contrary, a de- 
partment which will tend to increase the efficiency of his product. 
While the first cost of an up-to-date tool-room equipment is 
sometimes staggering to the person who pays the bills, the knowl- 
edge that through it he will be able to more than balance the 
expenditure in a very short time should set his mind at ease. 

The universal milling machines now on the market have been 
designed and built to meet all requirements of tool-making and 
manufacturing, while the attachments which may be used with the 
machines make the doing of a special or an intricate job an easy 
matter. With the attachments now in use on the universal miller 
for rotary-milling, cam-cutting, rack-cutting, vertical-milling, 
under-cutting large gears, and a variety of other classes of work 
too numerous to mention, the making of tools of unusual accuracy, 
as well as the modern manufacturing of machine parts, can be 
carried on without trouble or worry on the part of the mechanic. 

"KNEE TYPE" OF UNIVEBSAL MILLING-MACHINES. 

While fully appreciating the value and adaptability under 
certain conditions of the "Lincoln," "Slab," and "Botary 
Planer" types of milling-machines, I devote the space at my 
command herein to the ' ' Knee Type ' ' exclusively. This type 
of milling-machine, on account of its wide range of work, has 
been adapted for tool, die, experimental, and fine machine 
work all over the world ; and therefore, as the demand for this 
type of milling-machine has exceeded that for all other types 
combined, the tendency among the manufacturers of such ma- 
chines has been to increase their range and to make them uni- 
versal in every sense of the term. 

The knee-type milling-machine is among the latest additions 



124 TOOL-MAKING AND 

to the machine-tool family; but it lias taken its place in thou- 
sands of progressive shops, where it is used to the best advan- 
tage as far as the knowledge of the art has progressed at this 
date, although there yet remain many shops where its advantages 
are not understood, and work is being done on other machines, 
or by hand, when it could be done on a milling-machine at a 
great saving in cost, if a little thought were given to the proper 
cutters and equipment. 

The knee-type universal milling-machine will do a greater 
variety of work than any other machine tool, and a small experi- 
mental shop that can have only one machine will be best equipped 
with a machine of this class. 

MILLING-MACHINES COMPAEED WITH OTHEE 
MACHIXE-TOOLS. 

Any work that can be done on the face-plate or in the chuck 
of a lathe can be done in a milling-machine by holding an ordi- 
nary lathe-tool in the swivel-vise. A pair of bevel-gears, for 
instance, can be bored, turned on the angles, teeth cut, and the 
gears finished complete without ever having been near a lathe. 
A steam- or gas-engine cylinder can be bored, faced, and finished 
complete, and the fly-wheel bored and turned in the same ma- 
chine. 

What a trying thing it is to see a machinist work up a num- 
ber of parts on a shaper or planer and then see another spend 
a day or two filing and fitting to make them go together, while it 
takes a helper five minutes to mix them up and another machin- 
ist a long time to sort them out and assemble in their proper 
places. 

By way of contrast, a boy could have made them absolutely 
interchangeable in the milling-machine, and they could have 
been drawn at random from the stock-room and assembled with- 
out filing, fitting, or loss of time. 

Formerly it was supposed that a milling-machine in the tool- 
room constituted a full equipment in this line of machinery, but 
lately it is becoming known that improvements have been made 
greatly increasing the power of the spindle and feed, as well as 



INTEECHANGEABLE MANUFACTURING. 125 

adding innumerable conveniences, such as all automatic feeds 
constructed so as to be quickly changed from one to the other, 
and at the same time being impossible for any two to engage at 
once. The knee being box section, cast without hole through 
the top, gives the work-table sufficient rigidity to enable it to 
carry much larger work without chatter than would be possible 
with the old-style construction, and make many manufacturing 
operations not only possible, but economical. 

An equipment for the rapid production of finished work on a 
milling-machine can be classified under three heads. 

First : Strong, accurate machine with ample range and easy 
adjustments. 

Second: Suitable fixtures for holding the work where the 
pieces are large or complicated so that they cannot be held in a 
vise or easily clamped to the table (it takes skill to lay out and 
block up work on any machine). A suitable fixture makes it 
possible to use less skilled workmen. 

Third: Well -designed cutters, and a good cutter-grinder to 
keep them sharp. 

THE MILLING-MACHINE IX THE TOOL-BOOM. 

The fate of many a manufacturing concern rests with its tool- 
room, for here are produced the jigs, dies, fixtures, boring-tools, 
reamers, etc., suitable for the specialties manufactured. 

Do not consider it a necessary evil because it is classed as 
non-productive, for it is the equipment of well -designed, well- 
made tools that enables machine tools, standard and special, to 
come up to their highest efficiency, and place the factory in the 
fore-front. 

The machine-tool equipment should be all that would be re- 
quired to make a complete high-class small machine-shop, and 
the tool-making should be confined to it as far as possible rather 
than break up machines engaged in manufacturing. 

MILLING AN ANGLE-PLATE. 

Here the universal milling-machine is at home, provided it 
is a first-class machine and equipped with vertical-spindle and 



126 



TOOL-MAKING AND 



rack-cutting attachment. A machine of this kind will have the 
greatest possible accuracy, convenience, and range, and will be 
found adapted to every variety of tool-room work. A long auto- 
matic cross-range on a miller is also desirable, as it makes it an 
excellent tool for accurate jig-boring. Fig. 119 shows an angle- 
plate used on the face-plate of an engine-lathe for accurately 
boring a complicated piece that has two holes at right angles to 
each other. The angle-plate was first milled on the edge in 
order to provide a surface that would set square on the work- 




FlG. 119. 

table. The hole on the back for the lathe-spindle plug was first 
bored, and the plate shifted to the position shown. It is obvi- 
ous that these two holes will be exactly the same height from the 
edge of the plate, and the work when placed upon it will be in 
line with the lathe-spindle. If the piece had been a box-jig, a 
long boring-bar would have been used and the outer end sup- 
ported in the overhanging arm. Usually it is better to make 
boring -bars to fit in the taper hole in the spindle, as the chuck 
takes up some room. The chuck method, however, is very con- 
venient, as the boring-tool need be only a straight piece. 



INTERCHANGEABLE MANUFACTURING. 



127 



CIECULAE JIG-MAKING ON THE MILLEE. 

It often happens that an accurate circular- jig is required so 
that the two pieces drilled will fit without matching holes. This 
can be quickly done, as shown in Fig. 120. Note that the divid- 




FIG. 120. 

ing-head has cross-slot and side-ears so that blocking and strap- 
ping are unnecessary, and the large dividing-wheel insures 
accuracy. 

VEETICAL-SPINDLE MILLING-MACHINES. 

In establishments where large numbers of machines, appli- 
ances, and parts of standard shape are produced, the chief desire 
is the increasing of the daily output without increasing the labor 
cost. This desire can only be gratified satisfactorily by using 
machines which can be kept constantly producing parts of the 
same shape and size. It is in shops of this class that the vertical- 
spindle milling-machine can be used to the best advantage for all 
work that can be produced economically by vertical milling. 

As much time, skill, and money have been expended in the 
development of this type of miller, the advantages to be gained 
through its use are numerous, and are now almost universally 
recognized where economic production is imperative. The util- 
ity of vertical millers for machining surfaces and parts, once 
only thought possible to do on the lathe or on the planer, is 
steadily progressing, as the degree of precision to which the 
machine has been developed, namely, permanency of alignment 
of the spindle with the platen, makes the production of accu- 
rate and intricate parts by its use assured. 



128 TOOL-MAKING AND 

DOUBT AS TO THE UTILITY OF MILLIXG- 
MACHIXES. 

To those who are in doubt about the utility of milling-ma- 
chines plain, universal, vertical, and those in combination with 
other machines for modern manufacturing, tool-making, and 
machine- jobbing, a trip of inspection through the establishments 
devoted to their production would convince them; as in such 
shops they " practise what they preach " and have adopted their 
own machines for the rapid and accurate production of parts of 
machines of the same kind with the most gratifying results, the 
machines being used to the exclusion of all other machine tools 
on all jobs permissible. Thus in those shops the milling-ma- 
chine is practically self-producing, and stands to-day a monu- 
ment to the ingenuity and skill of those men who conceived it 
and developed it to its present high state of perfection. 



CHAPTER IX. 

Simple Milling Fixtures. 

SIX DISTINCT TYPES OF SIMPLE MILLING 
FIXTURES. 

HAVING in preceding chapters described various types of 
fixtures and tools suited for machining different grades of dupli- 
cate work by drilling, I Avill now turn my attention to milling 
fixtures; and will devote this chapter to those adapted for 
machining the simpler grades of work in which no great accu- 
racy is required, but which, at the same time, it is necessary to 
produce to a certain degree of interchangeability. 

In the construction of tools and fixtures for the machining 
and duplication of interchangeable machine parts by milling, a 
number of obstacles must be overcome that are not met with in 
the fixtures and jigs described in preceding chapters. There are 
also, of course, a number of practical points in their design and 
construction which are absolutely essential to their successful 
operation ; the conditions under which they are operated being 
totally different from those under which drilling-jigs and fixtures 
are used. It does not require as high-grade skill to construct 
fixtures for accurate milling as for accurate drilling, yet the 
designing of these fixtures entails considerably 

D 

moT^e thought and practical ability, to give 
satisfactory results. 

In Figs. 121, 122, and 123, are illustrated 
three samples of work milled by the use of in- 
expensive fixtures which may be aptly termed 
< i emergency fixtures. " The fixtures are shown 
in 124, 125, and 126. The design and method of construction are 
very simple, and are clearly shown in the illustrations. The fixt- 
ure for milling the square channel at B B, Fig. 121, is shown in 
9 120 




130 



TOOL-MAKING AND 



Fig. 124. It consists of a square plate L, of -inch flat machine- 
steel, finished all over; of the central locating-stud J screwed 
tightly into the centre of the plate; of the 
end locating-pin K, and of the two dowel- 
pins // which coincide with two holes 
drilled and reamed to size in one of the 
steel jaws of the miller-vise. The channel 




1%!. 



L is used as a guide for the cutter, 
as a gauge for the depth and loc 



the cut in the work. This fixture is located 
on the inside of the vise- jaw by the dowels 
II, and the stud J is entered into the reamed 
hole A of the work, and one side of the rough- 
cast channel B set against the locating-pin K 
as shown. The vise is then closed and tight- 
ened against the work, and the cutter is set 



uid also 
it ion of 




G G 

FIG. 123 




to enter the guide-channel L of the fixture, so 
that it will just touch the bottom of it. One end 
of the work is then milled; then the work is 
reversed on the fixture, so that the finished 
channel will locate against the stop-pin K, and 
the other end is finished. 

The other two fixtures shown in Figs. 125 
and 126 are also Constructed to locate on the 
stationary jaw of the miller- 
vise. That shown in Fig. 12;"i 



gJN 



is relatively the same as the first, except that 
no stop-pin is required the work, Fig. 122, 
being round and having but one slot, 7), 
milled in the position shown. The hubs of 
the work are faced and the hole C is reamed 
to size, the outside being finished to a given 
diameter in the lathe before milling. Fig. 
126 shows a fixture used for milling the 
channel in the face of Fig. 123. The two sec- 
tions are of cast-iron. The largest one, Q, has a raised projec- 
tion at one end, with a guide-channel R milled central with the 
V on the face. 8 8 are the two vise jaw-dowels, and T the 




FIG. 125. 



INTERCHANGEABLE MANUFACTURING. 



131 



sideway locating pin for the work. Both these fixtures are 
operated in the same manner as that shown in Fig. 124, and 
are adaptable for milling a large variety of small machine parts 
that are not required in large quantities, or in which a given 
limit of error is allowed, thus necessitating the utmost economy 
in the expense of the fixtures for their duplication. The efficiency 
and practical value of these three fixtures are at once apparent. 



FIXTUEES FOE MILLING A BEAEING IN A 
BEACKET. 

A plan and a side view of a simple fixture that can be 
adapted for odd-shaped castings are illustrated in Fig. 127. 
This fixture is used for milling the bearing and cap-surface of 
the bracket, Figs. 128 and 
120, to the shape shown at Y 
and Z Z respectively, the bear- 
ing Y being milled to an ex- 
act half-circle of the radius 
required, so as to conform 
with its duplicate in the cap. 
This is afterward fastened to 
the bracket and the bearing 

ils us 





FIG. 126. 



FIG. 127. 



reamed to the finish size. The fixture consists of one main cast- 
ing in the form of an angle-plate. When the base has been fin- 
ished, the tongue J fitted to the central slot of the miller-table, 



132 



TOOL-MAKING AND 



and the two holes drilled for the fastening-bblts, the angle-plate 
is set up on the miller, facing the spindle. The face is then 
milled, ending in a square shoulder at the locating-surface /. 
The two clamps C C are then made, and holes drilled in the 





FIG. 128. 



FIG. 1J*. 



face of the angle-plate to admit their bolts J) I). Locating set- 
screws E E are then let into the back extension-lug B and 
fastening-screws G G let into the front lug, as in plan view, Fig. 
127. Both views of the fixtures show clearly the manner of lo- 
cating and fastening the work on the fixture. With the use of 
this fixture one can rapidly locate and fasten the work, the 
clamping arrangements insuring the rigidity of the work when 
presented to the cutter. As will be seen, there is a projecting 
surface F at the top of the front extension-lug; the face of this 




FIG. 130. 



lug is milled square with the face of the fixture, and acts as a 
gauge-point for setting the "gang " mill the proper distance from 
the locating -face of the fixture. Fixtures of this design should 
be used wherever possible, as the small number of parts and 
rapid handling commend them. 

FIXTUEE FOE USE IN SQUAEING THE ENDS OF 
DUPLICATE PIECES. 

Fig. 131 gives two views of a milling-fixture which is (to the 
best of my knowledge) new in design and has possibilities for a 



INTERCHANGEABLE MANUFACTURING. 



133 



wide range of work of the type shown in Fig. 130. This work 
is a square-threaded screw with duplicate ends. The ends were 
required to be squared so as to be exactly in line with each 
other, as shown at K K. The fixture is made to accommodate 
six screws at a time, and is made in two sections, Fig. 131. 
These sections are of cast-iron, finished and squared all over, 
and doweled together by pins Q Q, one at either end. The spac- 
ing, locating, and finishing of the six work-receivers, two of 
which are shown with the work NNin position, is accomplished 
in the milling-machine by means of a special counter-gore. This 
finishes them so that a perfect half-form remains in each section, 




FIG. 131. 

with the shoulder of each at O exactly the same distance from 
the top of the sections. A cut is then taken off the face of each 
section so that the work may be clamped securely. The most 
interesting feature of this fixture is the manner of locating the 
work within it so that the second operation of squaring the ends 
will be accomplished with ease and expedition. This is done by 
milling a slot crosswise through the bottom of the sections at the 
side of each receiver to accommodate the locating-plates P P P P 
P P as shown. These slots, or channels, are so finished by the 
use of the graduate-dials on the table feed-screw of the universal 
miller that when the plates P are driven tightly into one of the 
sections, and extending into the other (the slots in which must 



134 



TOOL-MAKING AND 



be slightly enlarged to allow of their entering freely), one of the 
squared sides of the end of the work milled with a gang-cutter 
in the first operation will rest squarely against them. When in 
use the six plates P are first removed and the two sides of one 
end of the work milled with a gang-cutter. When all have been 
treated in this manner the six locatmg-plates Pare again inserted 
in their channels and the ends finished ; requiring three opera- 
tions, as follows: First, enter the ends of the screws that have 
been milled, so that one of the sides rests squarely against the 
locating-plate ; then mill two sides of the other end at right 
angles with those milled on the first end. Now, by reversing the 




FIG. 132. 

screws, the remaining two sides of the first end can be finished 
square with the other two. This operation is repeated and the 
ends again reversed, thereby finishing both ends square and ex- 
actly in line with each other. The use of this fixture enables 
duplicate parts of the work to be finished exactly alike, and, 
what is more, the squaring of the ends, which is usually a slow 
and difficult job, is thus accomplished with ease and rapidity. 

FIXTUEES FOE USE IX SLOTTING AND DOVE- 
TAILING SMA^L PIECES. 

Two examples of a somewhat different type of milling fixture 
are illustrated in Figs. 133 and 134. These fixtures are used for 
milling the casting shown in two views in Fig. 132, and embody 



-T-' 



INTERCHANGEABLE MANUFACTURING. 



135 



in their design and construction a number of practical points 
which are suggestive. 

That shown in the two views of Fig. 133 is used to mill the 
square channel at E and the slot D, Fig. 132. The drawings 
clearly show the method of construction. The work is located 
centrally on the stud K, and side wise against the stop -pin N, the 
clamp P holding it tightly and securely against the face of the 




angle-plate J. The guide -channels M M M M are for the large 
cutters, and L L L L for the slottiug-cutters. The angle-plate, or 
fixture proper, is well ribbed at the back, as shown at Q Q Q, 
and is located true on the miller-table by a " feather' 7 in the 
channel cut in the bottom. When used in conjunction with a 
set of gang-mills this fixture is a very rapid and accurate pro- 
ducer. The guide -channels in the fixture enable one to set the 
cutters to take the proper depth of cut and to locate them cen 



130 



TOOL-MAKING AND 



tral with the hole B in the work, Fig. 132. When in operation 
the cut is against the fixture, thereby holding the work rigidly 
against its face. 

Fig. 134 shows two views of a fixture which, although very 
simple and inexpensive to construct, has much to commend it. 
It is used for milling the dovetail in the end of the casting 
shown in Fig. 132, and will accommodate six castings at a time. 
It consists of the two end angle-brackets B B, the central locat- 
ing- and clamping-arbor C, and the locating-bar 0. The ond- 




Fiu. 134. 

brackets B B are first bored out and the hubs faced, and then 
they are placed on an arbor and the base of each is milled with 
the tongues E E in line with each other. A square hole is now 
let into the face of each bracket at F as shown, and finished to 
ske and in line by clamping both brackets together and forcing 
a broach through the unfinished holes. The locating-bar G is of 
square tool steel, finished all over for its entire length, to fit 
nicely within the holes in the face of the brackets. The width 
of the bar is made to fit the square channel E, Fig. 132, previ- 
ously milled in the castings or work. When the fixture is in use 



1NTEECHA NGEA BLE MANUFA CTUEING. 



13; 



the bracket B at the right is clamped securely on the miller- 
table, and the one at the left slipped off the arbor C. The six 
castings I are then slipped onto the arbor with the square milled 
channel of each down, so that the locating-bar G rests within 
them. The left bracket is then slipped on and the nut K tight- 
ened slightly. By tightening the screws in the ends J of the 
casting, the channels are clamped to the locating-bar G. Nut IT 




p 




p 


M 


O 



N 



PLAN VIEW 




Q 




JU!!U_ 



M 



SIDE VIEW 



FIG. 135. 



is then tightened securely and the bracket firmly clamped to the 
table: By the use of the vertical attachment and of an angular 
cutter, the six castings are milled and finished to the shape 
shown at F, Fig. 132, and at K, Fig. 134. 

The points to be considered when designing fixtures for mill- 
ing in one operation a number of small parts of the type hero 
shown are as follows: First, the number which can be handled 



138 



TOOL-MAKING AND 



to the best advantage; second, the manner of presenting the 
work to the cutters, and, lastly, the most expeditious and relia- 
ble means for locating and holding the work rigidly while being 
milled. 

FTXTUBE FOE USE IN GA^s T G-MILLING. 

A type of fixture used" extensively for gang-milling, where 
wide surfaces or a number of depressions are to be milled in the 
face of castings that have not been previously machined, is shown 




in Figs. 135 and 136. Although of the simplest construction, it 
represents a useful type of milling fixture for the milling of a 
large variety of work that it would be difficult to machine rap- 
idly by any other means. This fixture is used for the milling of 




FIG. 137. 



the type of casting shown at H, Fig. 137, which consists of four 
channels H H H H in the face, and of the square channel I in 
one end ; requiring two separate operations ; both being accom- 



INTERCHANGEABLE MANUFACTURING. 



139 



plished on the one fixture. Fig. 135 shows a section of the 
plan and side view, and also an end view of this fixture which 
handled eight castings at once. It consists of one large casting M 
having two half-round depressions running down its entire 
length as clearance for the projections on the back of the work. 
The top is planed true with the base as a squaring surface for 
the work, and ends in a square shoulder at N for the work to 
locate against. The work is held in position by clamps at It R 
so placed as to clamp two castings, as shown at P P. The holes 
for the bolts are counterbored at the back to allow the heads to 
clear the miller-table, as at T T in the side view, Fig. 135. The 
work is fastened as shown, and the square channel in the end is 
milled. When all the castings have gone through this operation, 
the four channels are finished by relocating and fastening the 
work to the fixture and setting a gang of mills. The cross-slide 
of the miller-table is then clamped, the depth of the cut set, and 
the castings finished. 

FIXTUEE USED IN FACE-MILLING. 

Another type of simple milling-fixture is shown in the two 
Views of Fig. 138. Although somewhat similar to that shown in 




a.1 \z 



w 



111 A 



FIG. 138. 



Fig. 135 it is used for a distinctly different class of milling; 
that is, face-milling. The sketch shows it being used for ends V 



140 



TOOL-MAKING. 



V of castings like Fig. 139. This casting is first set up on the 
planer and the dovetailed slide-surfaces U U are planed to 
gauge. The fixture is constructed to handle two castings at 
once, they being located side wise by forcing the side of one of 
the dovetailed surf aces Z agai nst the angular-faced locating-lugs 
X-X X X as shown, and endwise against the squared and 
faced projections Y Yat the back. The castings are held in po- 
sition by two clamps each, as at C C C C, and the heads of the 
bolts are let into the base, as at A A in the side view. The ends 
of the castings are faced by a large cutter-holder, with self -hard - 



= U 




= u_ 




FIG. ]9. 

ening steel cutters set into the rim, so that a roughing and finish- 
ing cut can be taken at the same time. When one end of the 
casting has been faced, they are reversed, relocated, and the 
other ends are faced. 

When the large variety of machine parts, both small and 
large, which can be machined in exact duplication of each other 
by the use of just such simple and inexpensive fixtures as are 
here shown is considered, it is surprising that these methods of 
manufacture had uot been adopted more extensively. By this 
we mean in the small shop ; for in the large shops, unless the 
machines or appliances are manufactured under patents, it is 
absolutely necessary to manufacture by the interchangeable sys- 
tem in order to meet competition. 




' 



CHAPTER X. 

Milling-Fixtures for Accurate Work. 

FACTORS IN THE SUCCESSFUL USE OF ACCURATE 
MILLIXG-FIXTURES. 

WE are now about to take up a class of milling-fixtures of a 
different type from those described in the preceding chapter, in 
that they are more intricate and are also capable of producing 
more accurate results. When designing these tools there are 
three questions to be considered : First, are the parts which are 
to be machined required in large quantities? Second, must they 
be finished very accurately, so as to be interchangeable'? Lastly, 
can the parts be handled and finished to the best advantage in 
the milling-machine'? 

The first two questions can be answered in very short order. 
But in deciding the answer to the last one, the knowledge and 
skill of the designer, who is often the constructor as well, are put 
to the test. If it is decided that the milling-machine is most 
suitable for the work, the following points must then be consid- 
ered after the shape and type of fixture have been determined: 
The surface by which the pieces are to be located ; the devices 
for fastening the work, and the most practical way of presenting 
the surface to be machined to the cutter or cutters, as the case 
may be. 

As types of the most reliable class of milling-machine fixtures 
for duplicating small and medium machine parts, there are here 
shown five examples which are well designed for the particular 
pieces of work for which they are intended. The devices also 
are suggestive, in that many of their features can be so modified 
as to be applicable to work of other kinds. Methods for con- 
structing the fixtures will be described explaining how they 
can be produced within a reasonable length of time and at mod- 
erate expense. 

141 



142 



TOOIj-MAKING AND 



FIXTURE FOR THE FIRST PIECE OF WORK. 

The fixture shown in three views of Fig. 140 is used for fac- 
ing the flat surface of the work, Fig. 141. The finishing of the 
ends of the piece is accomplished in the lathe, the parts e e, d d, 
and the threaded portions being interchangeable. The fixture, 
Fig. 1*40, for facing the flat surface F true witli the turned por- 




FIG. 140. 

tions of the work, is of few parts, and holds the work rigidly. 
As the method of construction is not very intricate, and can 
be understood from the illustrations, a slight description will 
suffice. 

The fixture proper consists of the body castings G, the stand- 
ards H between which the work is located, the back projection 
I for the fastening- and locating-screws N N and respec- 
tively, and the two clamping -lids J J. The lid clamping-screws 
L L are fastened in the slot in the standards, as shown in the face 
view, by means of Stub steel pins, so that they may be fastened 
and released as rapidly as possible. The lids J J are hinged as 
shown at K K. The locating-screws are of tool steel and are re- 
duced at the ends as shown at P, in the end view, and hardened 



INTERCHANGEABLE MANUFACTURING. 143 

and equipped with jam-nuts. The tongue TIs let into a slot in 
the body casting G so as to be perfectly in line with the turned 
portion of the work when within the fixture. 

The boring of the standards and lids to size, and the facing 
of the surfaces M M so that the work will fit between them 




FIG-, ill. 



snugly, is accomplished in the following manner : The base is 
first planed and the body casting strapped to an angle-plate on 
the drill-press table. A boring-bar is then used with the end 
running in the bushing in the table, and the holes are bored and 
the shoulders faced. The two screws N N for forcing the work 
against the two locating- screws O have knurled heads with a 
spanner hole as shown, are threaded to screw freely in the 
tapped holes, and are also equipped with jam-nuts. 

When using this fixture it is clamped on the miller-table with 
the tongue T in the slot nearest the spindle. The two lids JJ 




FIG. 142. 



FIG. 143. 



are then thrown back and the work located as shown, first tight- 
ening the lids, and then forcing the work against the two locat- 
ing screws by means of the knurled head-screw NN, and 
fastening the nuts to keep them tightly against the work. The 
cross-feed of the miller- table is then clamped so that the cutter 



144 TOOL-MAKING AND 

will remove the amount of stock required ; and the face is milled, 
using a large face-cutter, running it so that the cut will be down- 
ward, thereby taking the strain off the fastening-screws j\ r N and 
keeping the work against the locating-screws 0. The facing 
of work of this class in fixtures of the type shown can be accom- 
plished to a greater degree of interchangeability and in less time 
than by any other means known to the author. 

FIXTURE FOR USE IN MILLING THE SECOND PIECE. 

In Figs. 142 and 143 we have a milling fixture of a more in- 
tricate type, and one which for rapid locating, fastening, and 
releasing of the work when finished, would be hard to beat, as 
one turn of the screw fastens or releases, as required. 
This fixture is constructed for the accommodation 
[ d of two pieces at a time, and could, if required, be 
constructed for twelve on the same principle. The 
fixture was designed for milling work of the shape 
shown in Fig. 144. The piece was of machine steel 
and was finished, all but the milling, in the turret- 
lathe, and was used as a part of an electric cloth- 
cutting machine which was being manufactured in large numbers. 
The milling consists of a slot through the stem at a and a flat at 
either side of the largest circular portion, as shown at b />. 

The fixture consists of two castings, P and E, and spring- 
chuck devices, of which / 1 are tool-steel pieces screwing into 
the casting E and carrying the spring- jaws K. These jaws are 
forced out against the work by the expanders L L, which screw 
into threaded holes in 1 1. The one point in the construction of 
this fixture most worthy of a detailed description is the manner 
of finishing the locating-depressions F F in the part E. This 
part is of cast-iron, with a projecting lug at M which is used 
when finished as a gauge for setting the three cutters which mill 
the work. This cast-iron block is first planed on all sides, and 
one side N finished dovetail, to fit tightly into the dovetailed 
channel milled in the body casting P. This channel, by the 
way, was milled on the front of the casting and faced, after the 
base had been finished and the groove for the tongue was milled, 




INTERCHANGEABLE MANUFACTURING. 145 

on the machine on which the fixture was to be used, to guard 
against inaccuracy. 

The block E was driven into this channel and fastened by 
two screws, shown at R. The position of the centres for the lo- 
cating-depressions FFFF were then located so as to be dead 
in line with each other by the "button" method described in 
a previous chapter. The depressions were finished and holes 
bored and threaded at the back by strapping the block E on the 
lathe face-plate, truing the "buttons, "boring the holes, finishing 
the formed depression to exactly the shape and depth by means 
of a forming-tool, and then reversing the work and enlarging and 
finishing the holes at the back, as shown. 

When the fixture is in use, the work is held down on the lo- 
cating-face F F by hand, and the expander given a turn by the 
handle J. This causes the spring-chuck K to grip the work and 
draw it down on the locating- face. The cutters are then set by 
the gauge If and the work milled. 



DESCRIPTION OF FIXTURE FOE THE THIKD PIECE. 

In Fig. 145 there are two views of a piece which is an ideal 
job for the milling-machine. It is a cast-iron spindle-bracket, 
and the milling operation consisted of facing the fronts and 
backs of the two bosses, and finish- 
ing the projecting rib // at a cer- 
tain distance from centre of hole 
Q and at a right angle with the 
hole K. Before milling, the hole 
Q is bored and one side of the hub 
faced in the turret-lathe. The op- 
posite side is then faced and the 
two holes drilled through (j g and 
one through K. The side j is faced in a special jig and all 
points machined are interchangeable. 

The milling fixture shown in Figs. 146-147 is designed to 
hold two pieces of work at once, and can be constructed for the 
accommodation of a dozen, if desired. One casting, A, is all that 

is required for this fixture, and is in the shape of an angle-plate 
10 




FIG. 145. 



146 



TOOL-MAKING AND 



with projecting bosses at the front and back at B B as surfacing - 
points for the work, and four projecting lugs on the face, of 
which E E are for the locating-points and D D for the fasten- 
ing screws. For clamping the work in position a device is used 



A 


TOP VltW 


cf 


T; 




Q f|!!|!HiP " SECTIONAL VIEW, LOOKING AT LEFT END OF FRONT VIEW 

-IOWN SELOW 

FIG. 146. 

which allows the work to be fastened or removed with the great- 
est rapidity. It is shown clearly in the sectional view of the 
fixture, and consists of a stud M of tool steel, which is turned to 
fit nicely the hole I in the work and L in the fixture. It is of 




FIG. 147. 



the same diameter for its entire length and is threaded at the end 
P^for the nut 8 and reduced as shown in J^to admit the clamp- 
ing-washer Q. This washer is of tool steel and is knurled on the 
outside so it can be easily removed, and has a section cut out as 



INTERCHANGEABLE MANUFACTURING. 14? 

shown, for slipping it into the reduced channel N of the stud M. 
The locating-faces of the lugs E E are faced at right angles with 
the stud N, so that when the faced portion J of the work is 
forced against the locating-face it will rest perfectly flat and 
bear all over. The fastening-screws U U are reduced at the 
ends W W, ending in a square for the washers V V. The head 
of the clamping-stud M is milled with a flat on two sides for a 
wrench. 

When in use, the fixture is clamped to the miller-table with 
the tongue C in the central slot. The nuts P of the clamping- 
studs are then loosened, the work slipped on as shown, the 
clamping-washer Q Q located, and the nuts P tightened by using 
wrenches on them and on the end O of the studs. The work 
is then forced against the locating-lugs E E by the set-screws 
U U and milled, as shown, by setting a pair of straddle-mills 
for the proper depth of cut and clamping the cross-feed of the 
miller-table. To remove the work all that is required is to loosen 
the set-screw U ZJand the nuts P, slip off .the washers Q Q, and 
remove the work. The rapidity with which this fixture can be 
operated and the perfect interchangeability of the work pro- 
duced is surprising. The device shown for clamping the work 
is far superior to the usual methods adopted. 

INDEXING MILLING FIXTURES FOR LAST TWO 

PIECES. 

As there are a large variety of circular- shaped machine parts 
to be milled at different points regularly spaced, I show in the 
last two illustrations two types of indexing milling fixtures in 
which simple means are used for the attainment of the results 
indicated in the sketches of pieces shown in Figs. 148 and 149. 
The first of the two fixtures, the one shown in two views in Fig. 
150, is used for milling the six equally spaced channels M in the 
disk, Fig. 148. The castings for these parts are finished all over 
in the turret-lathe to the shape shown, and are then milled two 
at a time on the fixture, Fig. 150. The illustrations show a plan 
and cross-section view respectively ; as the design and method 
of construction can be understood from them, very little descrip- 



148 



TOOL-MAKING AND 



tion is necessary. A is the fixture proper, the work beiug 
located centrally on the studs E E, which are let into the base 
and located for height on the faced surfaces C C as shown in the 
cross-section. The holes in which the studs E E are located are 
bored sufficiently large to give clearance for the hubs of the 





FIG. 148. 



Fi. 149. 



work, as shown at D. The high projecting lugs B B B B are 
surfaced so as to allow the clamps N N N N, two to each part, 
to clamp the work securely. The indexing device is shown in 
the plan view and is self-explanatory. The projecting lug at the 




FIG. 150. 

right end of the work has a slot milled through it in a central 
line with the central locating-studs E E and to the depth re- 
quired, thus serving as a gauge for the depth of cut. 

When in use the work is located and fastened as shown, only 
that the indexing-pins are out. A cut is then taken down 



INTERCHANGEABLE MANUFACTURING. 



149 



through both parts, as shown by the arrows, to X X. The table 
is then run back, the clamps slacked, and the work moved until 
the index-pins H II enter the channels just milled. Tightening 
the screw J of each to hold it securely, the cutter is run through 
again and the operation repeated. The work is then removed 
by loosening the clamp-bolts and sliding the clamp back ; 
provision being made for this by slotting the bolt-holes of the 
clamps, as shown at Q Q in the cross- sect ion. By changing the 
location of the indexing device, work may be milled with any 
number of slots or grooves ; in fact, there is an inexhaustible 
variety of work for which fixtures of this design can be adopted 
with the best results. 

Fig. 151 shows two views of a fixture, the use of which dem- 
onstrates how work usually produced in jigs on the drill -press 
may be machined in a better manner by the use of simple fixt- 




TIG. 151. 

ures on the milling-machine. The fixture is used for counter- 
boring and facing the six bosses of the spindle-disk casting 
shown in two views in Fig. 149. The points previously ma- 
chined are the hole C, the six holes marked P, and the two hubs, 
all being finished to interchange. The fixture consists of the 
angle-plate A, which has a projecting hub on either side at 7) 
and J5, and the central locating-stud and the indexing-pin 0. 
After the angle-plate is planed on the bottom it is fastened to 



150 



TOOL-MAKING AND 



the lathe face-plate, and the hub D faced. A hole is then bored 
straight through the centre of the hubs and reamed to size, and 
counterbored to the diameter and depth shown in the sectional 
view, for clearance for the hub of the work. It is then trans- 
ferred to th,e planer, where the hub B is faced and the channel 
let in for the tongue. The central locating-stud is then finished 




FIG. 152. 

so as to shoulder at _ff, and reduced and threaded at the back 
end for the washer" K and the jam-nuts L L, so as to revolve 
freely without play within the fixture. The device is now drilled 
for the two hardened steel bushings, one at E for the index-pin 
O and one diametrically opposite at 8. To properly locate these 
bushings, the work is fastened on the central stud I and the 
hole for the index-pin bushing E is finished, first by drilling 
through one of the holes P in the work, which is then removed 
and the hole counterbored to admit the bushing R, as shown 
by the dotted lines. The hole through the bushing is lapped to 
exactly the same diameter as the six reamed holes P in the work. 
The index-pin is then made of tools teel the head being 
knurled as shown then hardened and ground to fit snugly 
within the reamed holes P in the work and the bushing E in 
the fixture, being located by entering index-pin through 
one of the holes P and into the bushing E ; the hole for bush- 
ing 8 is finished, and the bushing entered in the same manner as 
the other. 

To operate the fixture the work is fastened as shown, and the 
counterbore located in a taper-sleeve in the miller-spindle. 
The longitudinal and cross-feeds of the table are then manipu- 
lated until the lead or supporting stud of the counterbore, 
Fig. 152, is in line with and can be entered into the bushing 8. 
The work is then fed against the cutter until the required amount 
of stock has been removed, and the graduated dial on the cross- 



INTERCHANGEABLE MANUFACTURING. 151 

feed screw set at 0. The table is then moved back, index- pin 
removed, and the work revolved one space or until the next 
hole P is in line with the bushing R. The index-pin is then re- 
entered and the operation of counterboring and facing repeated, 
and so 011 until all six of the bosses have been machined in repe- 
tition. 



CHAPTER XI. 



Miscellaneous Milling Fixtures, and Special Tools 
for Similar Work. 

A MILLING FIXTURE FOR DRILL-PRESS TABLES. 

IN the machining of tables for three- and four-spindle sensi- 
tive drill-presses, one fixture is worthy of interest, as it is both 
simple and effective for the accomplishment of the work desired. 
It is also suggestive for other work. The fixture is used for mill- 
ing the dovetail in the table to fit the slide-surface of the base 
or lower column, and is shown in two views in Figs. 153-154. 



, VERTICAL MILLER 





Q _ 06^ 



O 






o| 



o|! | | P 

p 

FIG. 153. 

It is used, as shown, in the vertical milling-machine. The table- 
surfaces of the castings were first planed up, after which they 
were ready to be milled. The fixture consisted of one casting 
N in the shape of an angle -pi ate. This casting was first planed 
on the bottom and the tongues fitted to the slot in the 

152 






INTERCHANGEABLE MANUFACTURING. 153 

miller-table. A cut was then taken off the face, getting it as 
true and smooth as possible, as the face of the table located 
against this surface. The two gauge-pieces Q and R, respec- 
tively, were worked out and fastened to the angle-plate with 
dowel-pins and screws, so they would serve as locating-points for 
the edges and face of the table. Three holes P P P were 
drilled in the base of the angle-plate, as shown, for the bolts 

w 



-V 







P- 



o; 



o 



LIMIT GAUGE 




FIG. 154. 



used in fastening it to the milling-machine table. Holes were 
also drilled and tapped in the face for the strap-screws T T T. 
Three straps were then made of machine steel and bent at right 
angles at one end, finishing them so as to be in the position 
shown when clamping the table. 

The fixture was then set up and clamped to the miller-table, 
as in the position shown in the top view, and a table ready to be 
milled stripped to it as shown, resting and being located on the 
top pieces Q and R respectively. A screw-jack was then used 
to brace the extension part of the table at W, thereby taking up 
the downward strain on the table while the dovetail was being 
milled. The milling was then finished in two cuts, as shown at 
N in the upper view, milling it to fit the limit-gauge shown at 
the bottom. 

The use of this fixture gives a practical illustration of one of 
the various kinds of work for which the vertical milling-ma- 
chine is adaptable, as the operation shown can be accomplished 
in one quarter the time which it would take to do on the planer, 



154 



TOOL-MAKING AND 



or on the regular milling-machine where, in milling the dove- 
tail, the table would be strapped to the miller-table, which would 
have to be raised and lowered by hand while milling, which is 
both hard on the operator and on the machine as well ; as will be 
at once understood. 



JIG FOE MILLING DEILL-PEESS SPINDLE-HEADS. 

The jigs described and shown in the following were used for 
milling and boring drill-press spindle-heads manufactured by 
the interchangeable system, and are both reliable and cheap in 
design and construction. 

The spiudle-head is shown in two views in Fig. 155, and a 
slight description will tend to the intelligent understanding of 

the requirements and construction 
of the jigs. The operations on the 
head consisted of, first, the milling 
of the dovetailed A to fit the column 
of the drill-press; then the cutting 
ont of the two Ings E, thereby al- 
lowing sufficient spring in the spin- 
dle-head to tighten it to the column. The hole is then drilled at 
C for the clamping-lever. After this is done, the hole J> is bored 
and finished. This hole must be accurately located, as the pin- 
ion, when inserted, must mesh accurately with the rack on the 

VIEW J ' G F R MILLING > DRILL PRESS SPINDLE HEADS 








FIG. 155. 




FIG. 156. 



spindle, and in order for the heads to interchange the jigs must 
be accurately constructed. When casting the heads, the holes 
for the spindle and pinion are cored sufficiently small to allow 




INTERCHANGEABLE MANUFACTURING. 155 

of the holes being finished to size, in case of a slight variation in 
the location of the holes when cored in the casting. 

The jig used for milling the dovetail A in the head is shown 
in three views in Figs. 156 and 157 respectively, and is very 
simple in both design and construction. It consists of, first, a 
large flat casting E, for which a pattern of the size and shape 
shown was first made, and stock left 
sufficient at all locating-points to al- 
low of finishing. After a casting was 
secured, it was first set up on the 
planer and the back planed and the 

FIG. 157. 

tongues G G fitted to the central slot 

of the table of the large milling-machine. It was then 
placed on the table of this milling-machine, and clamped 
to the table at each end, H II. By viewing the cross-section 
shown in Fig. 157 it will be seen that the head is located at 
three points I, J, and K. The point I is milled out, as shown, 
to a radius approximately the same as that portion of the head 
which rests at that point, as shown. The points J and K are 
then milled so that the head will rest perfectly parallel 011 
the jig. In locating castings of the kind shown, the clamping 
portion must be located at the strongest point, especially in this 
case, as the milling is finished in two cuts, which are very heavy 
cuts. As will be seen, this jig is made to accommodate eight 
heads, and for clamping these, four studs and straps are re- 
quired ; each one clamping two heads, as shown at M M M M. 
The studs are of machine steel, turned and threaded at each end 
and screwed tightly into holes drilled in the jig. As shown, the 
straps are of -f -inch flat machine steel, cut off the proper length 
and dressed at each end at the grinder. The nuts II are faced 
upon one side and case-hardened. When all parts are assem- 
bled as shown, and the eight heads strapped and located in posi- 
tion, an angular end-mill, screwed and fastened on to the screw- 
arbor, is used for milling them. For gauging the depth of cut, 
a double-ended gauge of f -inch tool steel is used, one end to go 
in and the other end not to go in. For gauging the distance 
from the centre of the spindle hole to the faces of the cutter, a 
button-gauge is used, the bottom fitting the spindle hole (which 



15G 



TOOL-MAKING A XI) 



is rough) freely, and the piece of steel in which it is fastened 
resting on the table of the miller. The distance from the cutter 
to the other end of the gauge being correct, the work is fed in 
until the face of the cutter j ust touches the gauge ; the cross- 
slide of the table is then clamped, and the table is raised or 
lowered, as may be required, until the edge of the cutter rests on 
a slight projection on the end of the gauge. This is for locating 
the cut approximately central with the spindle hole. The mil- 
ler is then started, and the cutter allowed to run through the 
entire eight heads. The table is then fed back to the starting 
point and raised a sufficient number of thousands until the small 
gauge will just go in. The cut is then started and run through, 
then the heads are removed and another eight located and 
clamped. The operation is then repeated. 



MACHINING DRILL COLUMNS. 

The tools here shown were designed by the author and used 
for machining the upper columns of small, one-spindle drill- 
presses. The column is shown in position on the fixtures. The 




FIG. 158. 



points machined are the finishing of the slide-surface A A for 
the adjustable spindle-head ; the milling of the base M and of 
the back P, as shown ; and, lastly, the boring of the hole for 




INTERCHANGEABLE MANUFACTURING. 157 

the spindle through the column at L and through the spindle- 
head. 

The milling of the slide-surface is done first in order to have 
a reliable surface by which to locate for the following operations. 
The body of the fixture is a long casting, B, with a high projec- 
tion at each end, the one at E being a 
" V" for the body of the column, and 
the one at the other end flat and square 
with the base, for the head-supporting 
bracket L This bracket is of cast- 
irou, cored out at J so that the head 
of the column L will enter it, the in- 
ner side of J being open so as to allow of this. The bracket 
is fastened to the body casting by four cap -screws. A feather 
C is let into each end in a channel in the base to locate it 
in the slot of the miller-table, and it is fastened by bolts 
through the holes at D D. Two clamps at F and G are used to 
fasten the work ; F being nearly over the vertical ad justing -screw 
N. A knurled head-screw at H forces the head L against the 
locating set-screw K in the face of the bracket / and the two 
other set-screws K act vertically as locating- and fastening- 
screAVS. 

For the milling, a gang of cutters and a special arbor of the 
shape shown are used, the angle or first cutter being threaded 
with a left-hand thread to screw onto the arbor and force the 
other two cutters tightly together. The narrow cutter is to finish 
a flat along the extreme edge of the milled surface, and the large 
one is for milling the face. The last two cutters are keyed to the 
arbor. 

The fixture is first bolted to the miller-table, and the work is 
fastened upon it, adjusting all locatiug-screws so that approxi- 
mately the same amount of stock can be removed from all parts. 
As the variation in the castings is very little, if the first column 
has been machined correctly all the others will be. A gauge is 
used to set the gang of mills. The work is moved up to the cut- 
ters until the face -cutter is removing the required amount of 
stoek and the angle -cutter is touching the gauge. When the top 
is finished, the table is raised and the under side is finished, 



158 



TOOL-MAKING AND 



starting at D D. Before this fixture was designed, the finishing 
of the slide A A was done on the planer ; but by this arrange- 
ment the same results were accomplished in one-third the time 
and to a far greater degree of uniformity. 

For facing the base M and the surface P the fixture shown 
in Figs. 160-161 was used. This was made for three columns, 




only one of which is shown. The dovetailed slide-surface pre- 
viously machined is utilized for locating and fastening the 
columns. The fixture consists of one heavy body casting, with 




FIG. 161. 

three standards on which the work is fastened. The locating- 
surfaces at F F F, respectively, are finished on the planer, one 
side at E with a dovetail at the same angle as that of the ma- 
chined surface. Two angular-faced clamps G G, with clamp- 
screws H, are used for fastening each column. Two straps H H 
are also used; although they are not absolutely necessary. 



INTERCHANGEABLE MANUFACTURING. 



159 



The base M is finished first, doing the entire number of cast- 
ings. They are then reversed on the fixture and the backs P are 
faced with an inserted tooth-face milling-cutter, which is fast- 
ened in the vertical attachment. The 
same cutter is used for facing the bases 
of the columns. 

The boring-fixture is shown in Figs. 
162-163, in the side view of which the 
work is shown in position, with the 
spindle-head attached to the slide- 
surface, ready to be bored. The boring ' 
and finishing of the spindle hole in the 

head L of the column and in the spindle-head at one and the 
same firne is necessary in order to insure the alignment of 









FIG. 163. 

those holes. This fixture is rather more intricate and expen- 
sive than the two preceding; but the cost was approved by 
the result. 

The fixture is in the form of a tall angle-plate, with two 
standards N projecting from the inside of C for the locating- and 
fastening-points. These standards are cored at X, as shown in 
the end view, to clear the boring-bar. Bevel-faced clamps R R, 



160 TOOL-MAKING AND 

with clamp-screws P P, secure the work. There were two bush- 
ings, one at the top in D at E, and the other in the base J at H. 
The holes for these bushings were cored small in the fixture 
when cast, and were bred to finish size 011 the large drill-press on 
which the fixture was to be used. Before boring and finishing 
these holes, the other locating- and lining-points on the fixture 
were finished, and the piece was strengthened by fastening two 
wide and stiff machine-steel straps at the sides, as shown at 8 8. 
These straps strengthened the fixture considerably and insured 
its rigidity. 

The bushings E and /f were of tool steel, hardened and lapped 
to a good fit on the boring- bar, and then ground on the outside 
and forced into their respective holes. There were four lugs F 
with hardened set-screws G and check-nuts to resist side-thrust 
when boring the holes in L and Q. Large openings in the up- 
right at b b and c c were convenient for inserting, fastening, and 
removing the cutters from the boring- bar. 

The fixture rests on the base B on the table of the large drill - 
press, and the work is fastened as shown. The boring-bar is 
then slipped down through the bushings, and the table of the 
drill -press swung around until the shank of the bar can be driven 
up into the drill-spindle. The roughing-cutters are fastened 
in the bar and fed down through the holes. The bar is then 
raised; the roughing-cutters are removed; a finishing set is sub- 
stituted, and the holes then finished. 

The boring fixture here shown w^as used only for machining 
single-spindle columns; for the two, three, four, five, and six- 
spindle frames a special self-driven machine, that might be set 
to bore two columns at once, was used. In this machine the 
work was located and fastened upon it in the same way as here 
shown, the only difference being in the driving of the boring - 
bars or cutter- spindles by bevel-gears, and feeding them through 
the holes in the work by a pinion and rack, in relatively the 
same manner as on a self-feeding drill-press. 

CHIEF FACTOE IN MACHINE MANUFACTUEING. 

One of the chief factors in modern manufacturing of machine 
parts by the interchangeable system is the selection of the proper 



INTERCHANGEABLE MANUFACTURING. 161 

machines and tools for the accomplishing of the results desired ; 
those that will allow of the rapid machining of the work are, of 
course, the ones to use. It is a common sight in a great many 
manufacturing machine-shops to see work being laboriously 
performed by the use of inadaptable machines and tools, which 
could, by the use of a machine more adaptable for it, be accom- 
plished with ease and expediency. In fact, I have often seen 
machines standing idle while the work which should have been 
machined in them was being done in others which were not at all 
adapted for it. Thus we learn that in order to get the maximum 
of production from the minimum of labor we must always con- 
sider and select the machines which are the best adapted for the 
work ; as well as pay attention to the designing and construction 
of the tools and fixtures for the operations necessary to finish it. 
11 



CHAPTER XII. 

Special Tools, Fixtures and Devices for Machining 
Repetition Parts in the Turret-Latch. 

THE USE OF SPECIAL FIXTURES IN THE TURBET- 

LATHE. 

IF there is one type of machine tool that, more than any 
other, has taxed the ingenuity of the designer and the skill of 
the tool -maker to keep it supplied with work, it is the turret- 
lathe ; as the numberless varieties and classes of work which this 
great factor in modern manufacturing is capable of handling are 
enormous. When I state the above I do not refer to the com- 
moner classes of work produced in this machine, as the tools for 
their repetition and duplication are sufficiently well known and 
understood to make their use universal, and descriptions of them 
would be superfluous. I refer to the special, odd, and brain- 
racking jobs that are constantly coming along, for which the 
ever- resourceful tool-maker is required to construct tools so that 
the parts may be turned out rapidly and accurately. 

For the production of parts in large quantities in repetition, 
which can be finished by turning, boring, or facing, no other 
machine tool, when equipped with suitable tools, offers the ad- 
vantages or is better suited than the turret-lathe, or its elder 
brother, the screw-machine. To faciliate the production and 
the efficiency of the machines, and reduce the responsibility of 
their operators to the minimum, thousands of tool-makers 
throughout the country are constantly engaged in constructing 
devices, fixtures, tools, and arrangements. It is with these 
classes of tools that I propose to deal in this and the following 
chapter ; devoting this one to the use of special tools in the tur- 
ret-lathe and the next to the use of similar tools in the screw- 
machine. 

162 



INTERCHANGEABLE MANUFACTURING. 



163 



It will not be necessary to go into detail in regard to the 
standard tools used in connection with the various devices and 
arrangements shown, as their use is well understood, and it 
would be digressing unnecessarily to treat them or the machines 
in detail. In regard to the special tools, however, too much 
cannot be written. 

The variety of the tools shown and the description of their 
construction and use will warrant a careful perusal by the reader ; 
as they will be the means of suggesting modifications of the de- 
signs which can be embodied in tools for work other than that 
shown in connection with them. Tools of these types are great 
reducers of cost of production ; and the ability to devise and 
install them successfully is an enviable capability of the modern 
tool -maker. 



ATTACHMENT FOE FORMING IEEEGULAE PIECES 
FEOM THE BAE. 

The turret-lathe fixture shown in the accompanying engrav- 
ings is for forming pieces of irregular outline from the bar. It 




FIG. 164. 



FIG. 165, 



is adapted for work having considerable stock to be removed, 
and will duplicate the pieces very accurately and leave the fin- 
ished surface smooth and free from tool marks. As it is always 



164 



TOOL-MAKING AND 



ready for use and can be fastened in place on the turret-lathe 
and set for the results desired in short order, it should find a 
place in all shops where the value of the turret-lathe is appre- 
ciated. 

Figs. 164-165 are front and back views of the fixture com- 
plete, while Fig. 166 is a side view, as the fixture appears when 
bolted to the back of a turret-lathe cross-slide. The latter view 
also shows the manner in which the cutting-tool is presented to 
the work. 

The fixture proper consists of two main parts of cast-iron, the 
round base J and the body casting I, constructed to swivel on it. 




FIG. 166. 

The front G of the body casting is dovetailed and has a rib IT for 
the steel slide C. The ribs N N act as strengthening ribs for the 
front and also as bearings for the pinion and lever- stud 0. The 
steel slide C and an oblong opening E allow the rack to project 
through the front C and mesh with pinion Q. This allows slide 
C to be moved up or down by the lever at the side. The pinion, 



INTERCHANGEABLE MANUFACTURING. 



165 



stud Q is of tool steel and has a large bead at one end and is re- 
duced and threaded on the other for the lever and fastening-nut 
P. The lever and pinion are keyed to the stud. 

The front or face of the steel slide C is finished on an incline 
at approximately the angle that would be adopted for the front 
clearance of a lathe-tool. This is done so as to avoid having 
to give this clearance to the cutting-tool, which is fastened to 
the face of the slide, and requires clearance on the bottom only. 




FIG. 167. 

The cutting-tool, as shown in the side and front views, is located 
within a smaller channel in the face of the steel slide C, at D, and 
is held by means of the large cap-screw F. The cutting-edge of 
the tool is sheared oif at the angle shown in the front view, from 
A to B, so that it will remove the metal from the work progres- 
sively. 

The circular portions of the two main castings, Fig. 164, are 
so constructed that the body of the tool can be swiveled, there 
being graduations at U U to enable it to be set accurately at the 
desired angle with the work. The base J is provided with a 
tongue L which fits nicely in the slot for the tool-post in the 
turret-lathe cross- slide. The main casting I is hollow in the 
center to allow a centre hub of the base to project up through 
it. The bolt K, by which the base is secured to the cross-slide, 



166 



TOOL-MAKING AND 



passes up through this hub and thus it is not necessary to loosen 
the base when swiveling the body casting or tool-head. To set 
the tool-head the two nuts T T at the base studs are loosened, 
and the head graduations set to the angle desired. The nuts are 
then fastened, and the head is rigidly held in position. The 
manner in which the two castings are finished so as to locate true 
with each other and swivel, is shown at V Fin Fig. 166. 

As a practical illustration of the manner in which the fixture 
is used, there is shown in Fig. 167 a plan view of it as located 
and fastened to the lathe cross-slide, with the cutting-tool in 
position for finishing from bar stock the taper end of a mild 
steel tool-post. For this work a tail-stock, equipped with cen- 
tre, replaces the turret usually employed and supports the end 
of the piece being formed and also sets the gauge for length. 

In machining the part shown in Fig. 168, the stock is fed out 
the required distance, and the spring-chuck jammed. The tail- 
centre, which is very hard, enters the bar far enough to support 




h 



FIG. 168. 



it. The handle of the fixture is then grasped by the operator 
and pulled downward until the lowest point of the cutting-tool 
at A is somewhat near the centre of the revolving stock. The 
cross-slide of the lathe is then fed forward, and the tool com- 
mences to cut until the slide stops against the stop-screw and the 
edge of the tool has removed considerable stock. The slide is 
now held securely against the stop-screw by the operator press- 
ing down hard on the cross-slide lever ; then with his right hand 
he pulls down 011 the tool-head lever, thereby feeding the cut- 
ting-tool downward, and the stock is gradually removed by the 
shearing cut of the tool, and the bar is finished, as shown. As 
each portion of the tool's cutting-edge removes the metal, it 
passes below the centre of the bar and ceases to cut, so there is 



INTERCHANGEABLE MANUFACTURING. 



167 



only a narrow surface of cutting-edge of the tool removing metal 
at the one time. The machining of the work is thereby pro- 
gressive ; there is no tendency to chatter or mark the work ; and 
by having a good stream of oil constantly running on the work, 
a fine, smoothly finished surface is the result. As soon as the 
entire cutting-edge of the tool has passed below the cenrte of the 
bar, the lathe cross-slide is fed back to its former position, and, 
the cutting-tool raised for the next piece. In order to produce 
the best results, the cutting-edges of the tool should be left quite 
hard, and be oil-stoned to a perfectly straight and keen edge. 
The amount of clearance and shear has also considerable effect 
on the results, and must be determined by the quality and nature 
of the material which it is desired to machine. 

In Fig. 169 is an illustration of a piece of work, the taper 
surface G of which is finished by the use of the special fixture. 

G 




THE WORK 



FIG. 169. 




In Fig. 170 is shown a special turret-tool used for supporting the 
smaller tapered end R while the other part is being finished. 
The stock machined was a f -inch drill-rod, and the long taper sur- 
face was required to be finished as smooth and clean as possible, 
and slight changes were made in the tool slide to accomplish 
these desired results. The slide C of the fixture was replaced 
with another that differed from the first only in that the face 
was left straight and at a right angle with the cross-slide, instead 
of being inclined for back clearance. Thus, when the edge of 
the cutting-tool passed by the centre of the stock, the portion 
machined would rub against it, and with the stock rapidly rotat- 
ing, the friction was sufficient to give quite a polish to the ma- 
chined surface. 



168 



TOOL-MAKING AND 



In Figs. 172 and 173 are shown two samples of work, the 
formed surfaces of which were machined by the use of the fixt- 
ure here shown, and in Fig. 171 is a sketch of one of the cutting- 
tools used for them, from, which an idea of their construction 
may be gained. 

The great saving in producing work of this class direct from 
bar stock, in preference to using separate castings, has made the 




FIG. 171. 

turret-lathe as great a factor in the production of machine parts 
as the engine-lathe. For that reason any method or device 
which will add to the capacity of the machine and increase the 
sufficient of output should be adopted, and the fixture herein 
described is one which will do this. It can be easily adopted for 




| 3% 



vl 






. 



FIG. 172. 



- 2 
FIG. 173. 



pH 



work other than of the class shown, such as chandelier and elec- 
trical fixture work, where large quantities of ornamental knobs, 
joints, and various other parts are produced from large brass 
rods or bars ; and, in fact, for producing shaped pieces from the 
bar of steel, brass, fibre, or hard rubber. 



INTERCHANGEABLE MANUFACTURING. 



169 



BOX-TOOL FOE THE TUEEET-HEAD. 

In Fig. 175 is shown the pinion as tised in drill-press spindle- 
heads, and in Fig. 174 the tools used for the first operation. 
These pinions were of cold-rolled mild steel, and were roughed 
out and countered at each end in the turret-lathe. The box-tool 
shown in Fig. 174 and a cutting-off tool were all that were neces- 
sary for it. The box-tool is finished from a mild-steel forging, 
which is first centred, and the stem E turned to fit the hole in 
the turret, and both ends faced. It was then located on the 





FIG. 174. 

head centre and set to run true in the steady rest, and the hole 
bored in the face for the bushing G, which was of tool steel, 
hardened and lapped to size, to fit the stock to be worked. The 
set-screw L holds it in position. A hole is then bored and 
reamed through the stem E for the centre-drill K, which is 
fastened within it by the headless screw M. Two cutting-tools, 
I and J respectively, are let into the box as in the position 
shown: one, J, for roughing, set slightly in advance of the 
other one, J, which finishes. These two tools are hardened, and 
drawn to a light-straw temper ; a set-screw for each, on the side, 
holds them in position. When using the tool, the bar of stock 
is held in the spring-chuck, and the tools J and J", in the box - 
holder, set so as to rough down the stem B of the pinion-blank, 
Fig. 175, as shown, leaving enough stock to allow of a finishing 



170 



TOOL-MAKING AND 



cut being taken in the lathe, and then grinding them to size in 
a Lams grinder. The centre-drill K is set so as to centre the 
end of the stem at the same time. The use of the two cutters in 
the box-tool, as shown, acts very well, and reduces the time on 
the work considerably, removing the stock as it does all in 
one cut. The fastening of the centre-drill, K, as shown, also 
contributes to reducing the time, as well as centring the stem 
true. 



TWO SPECIAL CHUCKS FOE THE TUEEET-LATHE. 

In Fig. 176 are shown two views of a special chuck used for 
boring and facing the hubs of cast bevel-gears. This chuck, to- 
gether with the one shown in Fig. 178, is used for the machin- 




FIG. 176. 

ing of gears which are used in large quantities on cheap ma- 
chines, and their use allows of the work being produced in 'a 
very rapid manner, and to the degree of accuracy required and 
as cheaply as possible. The cross-sectional view of this chuck 
with the work in position shows clearly the -design and method 
of construction. The body K of the chuck is of cast-iron, and 
is bored out and threaded at the back to fit the spindle of the 
turret-lathe. It is then finished on the face and a clearance-hole 
bored at L, and the locating-seat M M for the gear-face fin- 



INTERCHANGEABLE MANUFACTURING. 171 

ished, as shown, by using the compound rest, and setting it over 
as required. The inside of the chuck is then threaded for the 
fastening-lid at P P. This lid is also of cast-iron, finished as 




shown, with two handles at Q Q and a clearance -hole E in the 
centre for the hub of the work. Six pins, two of which are 
shown at X X, serve to drive the work, by engaging the teeth of 




FIG. 178. 



the gear as shown. When in use the chuck is screwed on to the 
spindle of the turret-lathe and the lid removed. The gear, as 
shown at JV, is then placed within the chuck, with the driving- 



172 TOOL-MAKING AND 

pins within the teeth. The lid is then screwed on and forces the 
bevel-face of the gear against the locating-surface M M of the 
chuck, truing it and holding it securely. The hole is then bored 
at 0, and the hub faced by the use of the combination tool 
shown in Fig. 177. By the use of this chuck, the hole in the 
gear is bored and finished true with the gear-face, which in cast- 
iron gears is absolutely necessary, in order for the gears to run 
well when assembled. 

The chuck shown in Fig. 178 is of a much simpler design 
and construction; but is just as useful and rapid in production 
for the class, of work for which it is used as the other. It 
consists of one body casting A which is bored and threaded at 
back to fit the turret-lathe spindle, and bored on the face of the 
clearance -hole at C and at B B as a truing point for the gear- 
face of the work F. The work is fastened in position by the two 
clamps 1 1. The spring E around each of the clamp-studs con- 
tributes to the rapid locating of the work and its removal when 
finished. The work is driven by the stud steel pin L as shown, 
and can be located, fastened, and machined in a very rapid man- 
ner, as a turn of the thumb-nuts J J releases the clamps, which 
are raised above the work by the springs E E, and the work C 
can be slipped out and another gear located and fastened in its 
place in very short order. The hole is bored in these gears, and 
the hub faced by means of a tool similar to the one shown in Fig. 
177. After boring the hole, it is finished to size by the usual 
chucking-reamer and finishing "floating" reamer, which insures 
the hole being round and true. 



DETAIL SKETCHES OF TOOLS AND FIXTUEES FOE 
MACHINING PULLEYS. 

The set of tools of which sketches are here shown were de- 
signed by the author for finishing countershaft clutch-pulleys in 
the turret-lathe, and have been very successfully used for this 
purpose. It was desired to turn out the pulleys in large quan- 
tities, and to have the work accurately done, making them dupli- 
cates so far as their finished dimensions were concerned. The 



INTERCHANGEABLE MANTJFA CTUEING. 173 

tools were so constructed that the pulleys could be finished com- 
plete at one setting. 

The type of pulleys which this particular set of tools was de- 
signed to machine is shown in the two views in Fig. 179, and 
consists of a six-arm pulley of a common type. The points to 
be machined are as follows: The hole was to be bored and 
reamed and one end of the hub faced ; the sides of the rim were 
to be faced, and an interior portion of the rim bored and finished 




FIG. 1T9. 

on a very slight taper, as shown, for the friction or rubbing sur- 
face of the chuck ; and, finally, the face of the pulley had to be 
crowned and finished. 

Tn order to accomplish all these operations at one handling 
of the piece, all the tools had to be specially constructed for the 
purpose. They consisted of a chuck for holding the work 
while being machined, a combination and boring hub-facing 
tool, a turret fixture for boring and finishing the clutch portion, 
and a special compound slide-rest, with cutting-tools at the back 
and front. 



174 



TOOL-MAKING AND 



Two views of the chuck are show r n in Figs. 180 and 184, and 
the several parts of the chuck appear in detail in the other fig- 
ures. The chuck so holds the work that all points to be ma- 




FlG. 180. 



chined are easily accessible to the cutting-tools. There are nine- 
teen parts in the chuck. The body is a forging of mild steel, 

L I I 




FIG. 181. 



and is bored and threaded at the back to fit the spindle of the 
turret-lathe. There are three projecting lugs or false jaws JIT, 
as shown, and the faces of these were turned off to form three 



INTERCHANGEABLE MANUFACTURING. 175 



even supports for three of the pulley arms. The outside sur- 
faces K K of the lugs were turned to a suitable diameter for the 






FIG. 183. 



FIG. 184. 



purpose of locating the pulley in a central position by means of 
the inside of the pulley rim, which comes in contact with these 




JAW OF CHUCK 




W 



iw 



I'! 1 



FIG. 186. 



FIG. 187. 



FIG. 188. 



surfaces K K when the pulley is held in the chuck. The sur- 
faces K and I of each lug, therefore, determine the position of 



176 



TOOL-MAKING AND 



the pulley with sufficient accuracy for machining while the arms 
are clamped securely by the jaws 000. 

The construction and operation of the chuck will be clearly 
understood from the engravings, and it will be seen that the pul- 
leys can be clamped in position or removed very readily. The 
three jaws O which grip the spokes of the pulley and draw 
them against the faces of the false jaws, are moved in or out, as 
required, by simply tightening or loosening the wedge -screw P, 
which raises or lowers the wedges N, as shown in the sectional 
view of Fig. 184. In making the chuck it is interesting to tote 
that the finishing of the rectangular holes L and M, Fig. 181, in 




FIG. 189. 



which slide the wedges ^aiid jaws 0, was accomplished by the 
use of broaches of the type shown in Fig. 188. For such work 
the broach should be constructed with very coarse teeth on the 
lower end to take out the bulk of the stock. It will be noticed 
that the teeth on the two ends of the broach are so inclined as to 
give shearing cuts in opposite directions, the object of this being 
to break off the chips as the broach passes through the work. 
The upper end of the broach is left perfectly straight for about 
two inches and serves as a "sizer." The broaching of the holes 
is accomplished by forcing the broach completely through them 
under the power-press. The machining of the other parts of the 
chuck presents no difficulties and will be understood by reference 
to the figures. All parts except the body of the chuck are of 
tool steel, and all wearing surfaces were hardened and tempered. 
The combination boring and hub-facing tool-holder is shown 
in Fig. 189. After the hole in the pulley is bored and the hub 
faced by this tool, it is finished by the small chucking reamer 
and by a finishing reamer of t-he " floating " type, to insure the 
hole being true and round. 



INTERCHANGEABLE MANUFACTURING. 



177 



The special turret-tool for finishing the clutch portion of the 
pulley is shown in Fig. 190, and details of the parts in Figs. 191, 
192, and 193. The three cutting-tools are held in dovetailed 
channels finished to an angle of three degrees with the centre 
line of the fixture, this being the angle of the chuck surface on 
the interior of the pulley rim. Having the grooves finished at 




FIG. 190. 

this angle makes it easier to set the cutters correctly, and as the 
cutters are held by clamping they can be adjusted to remove the 
right amount of metal. 

In Fig. 194 is a plan view of the special compound slide-rest, 
with the cutting-tools in position. This slide-rest consists of the 
main casting A, which is fitted to the carriage of the turret-lathe, 
replacing the cross-slide; of the compound rest B and C, in 
which the gashing- or roughing-tools are held ; and of the face 
crowning- and finishing-tool fastened within the main casting A 




FIG. 191. 

in a dovetailed groove at the back, as clearly indicated in Fig. 
195. There are seven roughing-tools and two side tools, located 
in channels in the slide C and fastened by the set-screw in the 
strap D the six short ones for gashing the scale and roughing 
off the face, and the other two for facing the sides of the pulley 
rim. The face crowning- and finishing-tool is located in such a 



178 



TOOL-MAKING AND 



position in the body plate A that its cutting-edge will operate in 
a line tangent to the periphery of the pulley ; and as the tool is 
designed to make a shearing cut, the nietal is removed progres- 
sively from one side of the pulley to the other, thus reducing the 





:n 



FIG. 192. 



FIG. 193. 



strain and the tendency to chatter. A plan of the slide-rest is 
given in Fig. 194, and in Fig. 195 is the elevation, which also 
shows the manner of holding the pulley in the chuck. 

Ref erring to Fig. 195, it will be seen that the pulley is se- 
cured in the chuck by slipping the spokes into the notches of the 




FIG. 194. 



jaws and tightening the wedge-screws P so as to draw the spokes 
tightly against the locating-faces, as shown. The hole in the 
pulley is then bored and the hub faced by the combination tool 
shown in Fig. 189, after which the clutch portion is finished by 
the fixture shown in Fig. 190, the leading stud supporting the 
work while it is being machined, and remaining in the hole until 
the pulley has been finished. The face gashing- or roughiug- 
tools are next run in and fed sidewise about T 3 -g -inch, thus re- 
moving all that is necessary to clean them up. 



INTERCHANGEABLE MANUFACTURING. 



179 



To crown and finish the pulley, the whole slide-rest is fed 
out by the cross-feed screw of the carriage until the entire cut- 
ting-edge of the crowning- and finishing-tool has passed beneath 




FIG. 185. 

it and finished and sized ft to the shape and size required. The 
use of this set of tools insures an exact duplication of the work 
produced at a low cost. 

There is one thing that must not be lost sight of, when con- 
structing a forming- and finishing-tool of the type shown here, 




FIG. 196. 

for crowning the pulley : As the face or cutting-edge is finished 
and ground so as to take a shearing cut, and the tool is located in 
such a position in the main casting as to give it the required 
clearance-angle, the forming-face must be finished as shown at 
B, Fig. 196. As the tool is set at an angle with the face of the 
pulley, in order to produce the shape desired, one side must be 
considerably higher than the other, as at B. This should be 
figured out and a templet made, according to the degree of clear- 
ance given and the amount of shear to the cutting-face. 



180 



TOOL-MAKING AND 



TOOLS FOE MACHINING A SPECIAL CASTING. 

The hood-shaped casting shown in Fig. 197 formed part of 
an electrical appliance which was being manufactured in large 
numbers and, as it is a characteristic piece of duplicate work, 





FIG. 197. 

the method employed in its production may prove of interest to 
my readers. 

The operations necessary for machining this casting were, 
first, to drill and ream the ^-inch hole A; second, face the base 
B ; third, finish the circular portion C C given diameter and 




FIG. 198. 



taper; and, finally, to drill the ^-inch holes through the centre of 
each of the four parts D. The first and second operations were 
both performed in a turret-lathe with the casting held in a four- 
jaw chuck, as shown in Fig. 198. The hole A was first bored 



INTERCHANGEABLE MANUFACTURING. 



181 



with the usual turret boring-tool and reamed to size with a 
" floating " reamer. The work was then driven slowly, by throw- 
ing in the back gears ; and the second operation, that of facing 
the base B was performed by the use of a large face milling-cut- 
ter, placed on an arbor which was held in the turret-head, as 
shown in Fig. 198. This cutter was of the ordinary type of 
facing -cutter, except that the teeth, on the facing side, were 
staggered to prevent chatter. The cutter, which was driven by 
the key K was held in place on the arbor by the nut N and 
washer W. 

With this cutter it was possible to machine a large number of 
castings before it required to be ground. 

The third operation, that of finishing the circular taper sur- 
faces C C, was accomplished as shown in Fig. 199 by the use of 




FIG. 199. 



an end-mill in a universal milling-machine. The work was held 
on an arbor between the tail and dividing -head centres and the 
swivel carriage moved around until the table and arbor stood at 
the desired angle with the face of the milling-cutter. After set- 
ting the work so that the desired amount of stock would be re- 
moved, the cross- feed screw was clamped, and the work fed 
against the cutter by revolving the dividing-head by hand. For 
the last operation, that of drilling the holes D D, the jig shown 
in Fig. 200 was constructed. This jig was made in two parts, a 



182 



TOOL-MAKING AND 



body casting in which the work was located, and a lid W, which 
was hinged at one side and carried the four tool -steel bushings 
E E by means of which the holes were located and drilled. 

A hinged bolt and thumb -nut Q served to clamp the two 
parts together when the jig was in use. 

The bottom of the body was bored out to correspond in taper 
and diameter with the taper surfaces of the work at C C. Ex- 
tending inward from one side of this hole was a lug K in which 
was fitted the stop -pin Z. The stem of this pin, where it fitted 




FIG, 200. 



the stop-lug, was eccentric with the body of the pin, so as to pro- 
vide for adjustment, while the screw J locked the pin in place 
when the proper adjustment was attained. 

This pin was brought against one of the inner lugs of the 
castings, as at E, and thus located the lugs in the proper position 
to be drilled. 

When in use the swinging clamp Q is released and the lid W 
thrown back. The work is then slipped into the body and lo- 
cated within the taper seat and against the stop -pin Z. The 
lid is then brought down by grasping the handle S and as the 
spring pad U strikes the work, the tension of the spring 
enables it to force it tightly down on the locating-seat. The lid 
is then held down on the body casting with one hand, while the 
swinging clamp is swung up and fastened with the other. The 
casting is then drilled through the bushings E E. One of the 
best features of the jig is the impossibility of the chips and dirt 
interfering with the accurate and positive locating of the work. 



INTERCHANGEABLE MANUFACTURING. 



183 



A MULTI-SPINDLE DEILLING AND TAPPING AT- 
TACHMENT AND WOEK FIXTUEE. 

The special multi-spindle drilling and tapping attachment 
and its work fixture, shown in the accompanying illustrations, 
were designed by the writer. The work shown in Fig. 201 is a 
circular casting with a large central hole and six small holes a a. 
It was for drilling and tapping these six holes that the attach- 




FlG. 201. 

ment here shown was designed, and as it proved a great cost-re- 
ducer and allowed the required degree of interchangeability at 
the minimum of cost, its adaptability for a large variety of work 
is apparent. It also shows another use to which the ever handy 
and often idle turret-lathe may be put. 

The six holes for the casting are equally divided around a 
circle concentric with the large hole c c, and are drilled entirely 
through the bosses. The large hole is bored and one side of the 
bosses faced in a preceding operation in the turret-lathe, and 
the keyway is let in so as to be in the same relative position to 
the bosses in all of the castings. 

Fig. 202 shows, partly in section, the fixture complete and 
also several of the main parts. Fig. 203 is a plan, with the 



184 



TOOL-MAKING AND 



arrangement of the gears and their relative positions on the sta- 
tionary spindle-disk. As shown in Fig. 202, the attachment 
consists of three main parts, of which A is the driver, C the sta- 
tionary spindle and leading stud. The driver A, of cast-iron, 
was finished first, boring it out at the back and then threading 
it to fit snugly the spindle of the turret-lathe. A hole was then 
bored straight through from the face at B and threaded as 





FIG. 203. 

shown, getting it dead true. The front was then faced, thus 
insuring the lubrication of the entire surface. 

The stationary disk C, a circular casting with bosses 011 each 
side, to the number of thirteen on the front and seven on the 
back, was then machined. The central hole for the spindle D 
was first bored and reamed to size, a mandrel was driven in, and 
both sides were faced, leaving all the bosses the same height. 
We were now ready to locate and finish the holes for the six 
spindle-gears II and the intermediate gears K. A stud of tool 
steel was turned up, hardened and ground to fit the central hole 
in the disk tightly. We then finished up six buttons of the type 



INTERCHANGEABLE MANUFACTURING. 



185 



used for accurate jig-making, and ground them to J-inch on the 
outside and the ends perfectly square. The central stud was 
entered into the hole and one of the buttons was located the 
exact distance from the centre by using the verniers and deduct- 
ing the diameter of the stud and button. The button was then 
fastened to the disk by its screw, being located as nearly in the 
centre of the bosses as possible. The second button was located 
the required distance from the first and from the centre of the 
stud in the same manner, and this operation was repeated until 
all six buttons were located. 

The disk was clamped on the lathe face-plate and the central 
stud removed. The first button was trued and removed, and a 




FIG. 203. 

^-inch hole drilled, bored, and reamed entirely through the disk. 
The next button was then located, trued, and removed and the 
hole bored and finished in the same manner; repeating until the 
six holes were finished. We were now sure of the accuracy and 
position of the gears when placed, and the interchangeability of 
the holes when drilled. Before drilling and tapping the holes 
for the six intermediate gears, the gears were turned and cut. 

The drill-chuck spindles and gears were each in one piece and 
were mild-steel forgings which were first centred and faced the 
same length. The spindle portions G were turned to within 
.005 -inch of the finish size and the ends threaded for the nut, 



186 



TOOL-MAKING AND 



leaving a shoulder for the washer. The taper portion for the 
chuck was turned, leaving the same amount of stock for finish- 
ing as on the other end. The gear portion H was then finished 
to the required diameter, and all were finished in the grinder, 
with the portion G a smooth running fit in the reamed holes in 
the disk, and the sides of the gears ground perfectly flat and true 
with the spindles. The teeth were then cut. 

The six intermediate gears K also were of steel; and six 
shoulder-studs or screws were made of tool-steel for them. The 




FIG. 204. 

large, or driving-gear F was of cast-iron and was bored and 
reamed to the same size as the central hole in the disk ; the sides 
were ground as the others, and a keyway let in for fastening it 
to the spindle and leading stud D. The portion D of the stud 
turned within the disk after hardening. A second shoulder was 
left at M so that the space between it and the first would accom- 
modate the disk and the driving gear. A hexagon was milled 



INTERCHANGEABLE MANUFACTURING. 



187 



at M and the stud reduced for the remaiuder of its length, the 
end rounded to act as a leading stud and enter a reamed hole in 
the work fixture when in operation, to support it. The six holes 
for the intermediate-gear screws were then drilled and tapped, 
so that the gears would occupy the positions shown in the plan. 
After drilling and tapping the hole for the stud B B all parts 
were assembled, as shown, the chucks being driven tightly on to 
the spindles. 

The fixture for locating and fastening the work is shown in 
Fig. 204. The body casting is machined first. After being cen- 
tred it has the stem turned to fit the hole in the turret-head. It is 








-Work 

Fixtur 


e 

ffi 


& 


1 




o 


c 


4 











U 1 







FIG. 305. 

then reversed and held by the finished stem in a nose -chuck and 
the front is finished, first taking a cut off the two projecting 
bosses G G, then finishing the seat for the work and turning the 
hub D to fit nicely the large central hole in the work (under 
cutting it at the back to prevent dirt or chips from accumulat- 
ing), and, lastly, boring and reaming the centre hole E for the 
leading stud of the drilling and tapping attachment. Before 
locating and letting in the key F in the hub D the lid was fin- 
ished and fastened to the body casting and the holes for the drill- 
bushings were let in. 

This lid-casting is circular, with a large hole L in the cen- 
tre and raised bosses at the opposite sides where it is hinged and 
located to the body casting. These bosses were faced and a cut 
was taken oif one side of the casting for the bushing-heads to 



188 TOOL-MAKING AND 

locate. The lid and the body casting were then clamped to- 
gether so that the boss faces rested true with each other, and the 
hole for the hinge-screw If was let in, tapping it in the body 
casting and enlarging and reaming it to a snug fit for the large 
portion of the screw in the lid. The screw H was then let in 
and the hole J drilled and reamed for the taper locating-stud J. 
We were now ready to locate and finish the bush ing -holes. The 
taper locating-pin J was forced in tightly and a hardened and 
ground plug was finished to fit tightly the hole E. Then by 
using the buttons used for locating the spindle holes in the 
drilling and tapping attachment these six holes were located in 
the same manner. The hinge-screw H and the locatiug-stud J 
were then removed, the lid was clamped to the face-plate, the 
buttons made true, and holes bored and reamed to the required 
size. The bushings K were made of tool steel and forced into the 
holes in the lid. Three holes were then drilled and tapped in 
the body casting in the positions shown by the dotted lines in 
Fig. 204 to accommodate the clamp -screws. These three clamps 
are only used when tapping the holes, the lid being then 
removed. After the six clearance-holes for the drills and taps 
were drilled and the key let in so that the bosses of the casting 
would cam approximately correct, the fixture was complete. 

In Fig. 205 is shown the manner of setting up the multi -spin- 
dle attachment and the work fixture. The driver, or back plate 
of the attachment is screwed on to the spindle of the turret-lathe. 
A clamp-strap of |-inch thick flat iron, bent to the shape 
required, with a hole in the centre for the stud B _B, Fig. 213, 
and the ends bent inward and set-screws let in, was then secured 
with the ends fastened to the body of the lathe and the stud 
B B fastened to the strap by the nut, thereby locating and fast- 
ening the spindle-disk without the possibility of shifting when 
in operation. 

The work fixture was located by entering the stem into one of 
the holes in the turret-head, the slide moved up, and the fixture 
manipulated until all six drills entered the bushings of the fixt- 
ure. The fixture was then fastened, the lid was thrown back, 
the work or casting to be drilled located by the key on the hub 
of the fixture, as shown, and the lid or bushing-plate relocated 



INTERCHANGEABLE MANUFACTURING. 189 

by the taper plug. The lathe is started, and as the driver 
revolves, and with it the driving gear, the spindle-disk remains 
stationary, allowing the six drills to turn at the speed desired. 
The turret-slide is moved up, the six holes are drilled in the 
work, the finished piece removed and replaced by another, and 
the operation repeated. After all tlie castings in the lot have 
been drilled they are tapped by simply substituting taps for the 
six drills and removing the bushing-plate from the work fixture. 
The locating of the castings so that alignment of the drilled holes 
with the taps will be perfect is accomplished without any trouble, 
as the keyway in the casting brings them in the same location 
as in the first or drilling operation, and the three clamps hold it 
tightly in position. When tapping, the spindles are run at the 
proper speed and the work is brought up to the taps, the opera- 
tor keeping his hand on the shifter, and as soon as the taps have 
come through the holes the lathe is reversed and the taps are fed 
out. 



CHAPTER XIII. 



Special Tools, Fixtures, and Devices for Machining 
Repetition Parts in the Screw-Machine. 

FOUR SPECIAL BOX-TOOLS FOR THE SCREW- 
MACHINE. 

The tools shown and described in this chapter were designed 
for and used in the screw-machines, but many of the designs are 
adaptable with slight modifications to the turret-lathe as well. 

The tools shown in Figs. 206 to 209 are for making small tubes 
used for perforating leather shoe-tips. These tubes run from 
T V to i-inch in diameter, are made from drill rod, and are re- 





FIG. 206. 

quired to be finished with a smooth reamed hole through them 
true with the outside, and with one end chamfered to a sharp 
edge. Iii producing the larger sizes of tubes very little trouble 
was encountered, but for the smaller sizes (and they were required 
in the largest quantities) much trouble was met with. All trou- 
ble, however, was overcome and very good results attained by 
the use of the tools shown herein, 

Fig. 206 is for chamfeing the ends and centring the tubes. 
The body or box portion, of cast-iron, has a hole through it for 

190 



INTERCHANGEABLE MANUFACTURING. 



191 



the entering-tool I 7 and its adjusting-screw C. A hole is broached 
through the body for the chamfering -tool C, at an angle which 
allows the face of C to be ground square. The bushing G is of 
tool steel, is hardened and lapped to the size of the drill-rod. 



ML J J 




By chamfering the end of the tubes with this tool, before drill- 
ing and reaming the hole, a sharp edge can be produced. 

Fig. 207 shows the tool for drilling the tubes. The drill is 
held in a split bushing by the ad justing -screw K and round- 
head screw N. The bushing L is forced into the holder. 

Fig. 208 is for cutting off the tubes. On account of their 
smaller diameter it is necessary to support the stoc^k during the 
operation. The body of the tool is of cast-iron. The cutting- 
off tool is of a somewhat special construction. It is of a x -J-- 
inch stock finished all over to fit within the channel, and with a 





FIG. 208. 

groove in one side for the feather IT. The grooves Fon the bot- 
tom are for the collar of the feed-screw W. The cutting end of 
the tool T is finished to the usual shape required for such a tool ; 
as narrow as possible, according to the size of the stock. These 
three tools produce the perforating tubes to the degree of inter- 
changeability and accuracy required, and in a very rapid man- 



192 



TOOL-MAKING AND 



ner. The tubes, after being thus finished, are hardened and 
tempered to a dark blue, and are forced into radial holes in a 
mild-steel disk. Different combinations of sizes of tubes are 
]ocated in these disks, to produce the pattern desired in their 
leather shoe -tips and miscellaneous leather findings. 

The box-tool, Fig. 209, is of a distinctly different type from 
those above described ; it is used for pointing slender needle valves 
on an incandescent oil-lamp of well-known make. It is rather dif- 
ficult to point wire of small diameter by the ordinary means avail- 
able in the screw-machine, especially if the points are to taper 




FIG. 209. 

quite gradually, as at M. By the ordinary method the cutting 
surface of the tool would be so wide that it would be almost 
impossible to keep the wire true and hold it sufficiently rigid. 
The body or box portion of the tool is a forging of mild steel, 
with a rectangular hole at B and a tool-steel bushing at C. The 
cutting-tool E is fitted snugly into a square broached hole, the 
side of which is in line with the end of the bushing. The rear 
end of the tool is threaded for adjustment nut G. A bracket is 
fastened to the body of the tool, and the spiral spring, which is 
required to be quite stiff, is located as shown. A hole is let into 
the body at D as clearance for the angular-faced tool-post fixt- 



INTERCHANGEABLE MANUFACTURING. 193 

ure L. A channel F is let into the under side of the pointing- 
tool E, with a taper side at the rear coinciding with the taper 
of L. In first operation the cutting tool E is allowed to pro- 
ject, adjusting it by the nut G slightly beyond the centre bush- 
ing C. As the box -tool is brought up to the work, the wire 
enters the hole D. As the tool E begins to cut, the engager L 
commences to force the tool back, and continues to do so until it 
ceases to cut and the wire is pointed as shown. The turret is 
then brought back, and the spring causes the cutting-tool to 
resume its former position. 



SCEEW-MACHINE FIXTUEES AND TOOLS FOE 
MAKING SPEED-INDICATOES. 

The sketches herewith are of two special chucks and of a 
tapping-machine which were designed by Mr. W. J. Parker, 
foreman of the Fulton Machine Works, Broooklyn, the chucks 
being used for machining a casting (Fig. 210) which forms the 
body of a speed-indicator manufactured by that firm. The work 
on this casting was the boring out of the large circular portion 
A for the revolving dial -plates of the 
indicator ; the facing of the bottom B 
and of the hub around which the dials 
revolve, and the drilling of the small 
hole C in the centre of this hub. All 
this was accomplished in one opera- 
tion, after the work had been fastened 
in the chuck (Fig. 211). The second 
operation was the boring and reaming 
of a hole D (Fig. 210) for the spin- 
dle of the indicator and the finishing of a centre and thrust 
bearing for the end of it at E. Both chucks are used in the 
screw-machine in conjunction with a set of turret-tools for each. 
Fig. 211 shows the chuck used for the first operation. It 
consists of a circular casting having a hub at the back and a 
raised portion on its face for holding the work. The casting is 
fitted to the screw -machine spindle, and faced and bored to admit 

the large circular portion of the work as shown at L, being bored 
13 




FIG. 210. 



194 



TOOL-MAKING AND 



to a depth sufficient for the upper side of the work to project 
slightly above the face If of the chuck. The face of the chuck 
is milled away on each side of the square central portion H so 
that the work may be easily located or removed. J is a flat 



THE WORK 





FIG. 211. 

machine-steel plate, located on the face of the chucks by two 
dowel-pins K K and fastened by the four corner screws L L L L. 
This plate, while fastened to the main casting, is bored suffi- 
ciently to tightly clamp the edges of the large circular portion 
and for clearance for the cutting-tools. Fig. 211 shows clearly 




VERTICAL CROSS-SECTION OF 
CHUCK AND WORK 



FIG. 212. 



how the work is located and clamped on the chuck. The work 
is machined by the usual type of turret-tools. 

The second operation is accomplished by the use of the chuck 
shown in Fig 212, which is of distinctly different design from 
that of the chuck Fig. 211. It is a circular hub-backed casting, 



INTERCHANGEABLE MANUFACTURING. 195 

with a rather long, flat, projecting standard at H, fitted, as in 
the other case, to the screw-machine spindle and having the face 
of H machined flat and square with the face of F. The work is 
located on this projecting face at two points by K and J"; also 
at Jby a circular machine-steel disk fitting within the portion A, 
Fig. 210, of the work and fastened to the face H, Fig. 213, of 





Fl. 214. 

the chuck by screws and dowel-pins (not shown) and at K by 
the steel plate J, which, as will be seen, is fastened by screws 
and dowel-pins. For clamping the work to the chuck the 
swinging bracket and clamping-screw N are used, the construc- 
tion of which is shown in the cross-section view of Fig. 214, 
where the work is shown fastened upon the chuck. The work 
machined in these chucks is, needless to, say, perfectly inter- 
changeable. 



METHOD FOE FINISHING DUPLICATE WORK IN 
THE SCBEW-MACHINE. 

The special tools and fixtures here described were designed 
for the screw-machine, and consisted of an improved driver 
for the work ; a special arrangement of lathe centres, and a form- 
ing-tool and holder which will duplicate work without chatter- 
ing and without regard to pressure applied by the operator. 

The particular piece of work for which these tools were de- 
signed is shown in two views in Figs. 215 and 216 and is called 
a " goose-neck." It is a brass casting, and is finished at the 



196 



TOOL-MAKING AND 



taper end marked A. Before finishing this surface, the castings 
were centred at 0, and chamfered slightly on the inside at B. 
The first fixture made for the finishing operation was the special 

B B 





FIG. 215. 



FIG. 216. 



chuck, a cross-section of which is shown in Fig. 217. The body 
of the chuck was a casting of the shape shown, and was bored 
out at C C. It was first chucked in the lathe and bored out and 
threaded at G G to fit the spindle of the screw-machine, and then 




FIG. 217. 



squared up. It was then faced and the rim trued. A hole was 
bored and threaded at D to admit the centre JE7, which was fin- 
ished with a shoulder at F so as to allow it to rest squarely 



INTERCHANGEABLE MANUFACTURING. 



197 



against the face of the chuck. A square hole was then let 
through the face of the chuck to admit the driver J, which was 
made of f -inch round tool steel and bent as shown, and the end I 
finished to a smooth fit within the hole J. The round portion H 
of this driver was long enough to allow it to extend clear through 
the screw-machine spindle, and was connected to the wire-feed 
lever. This manner of connecting the driver allowed it to be 
forced out and in, thereby permitting the work to be located on 
the centres, and removed when finished, without stopping the 
machine. 

As the edge B of the work, Fig. 215, gives a very narrow bear- 
ing for the tail -centres, and as the work revolved very fast, it 




FIG. 21$. 

was not practical to adopt the ordinary centre, as there was a 
tendency for the end of the work to run hot and burr up. So, to 
overcome this, the special sleeve and running-centre, shown in a 
cross-sectional view in Fig. 218, were made. This fixture consists 
of a sleeve which was first bored out and tapped at the back end 
for the centre end -thrust screw M. It was then placed on an 
arbor and turned taper on the outside to fit the tail -stock, which 
had been fitted to the screw-machine. The end-thrust screw M 
was then made with thrust end finished flat, hardened and pol- 



198 



TOOL-MAKING AND 



islied. It was then screwed tightly into the sleeve. The run- 
ning-centre K was then made of tool steel and finished to fit the 
sleeve smoothly, and tapered at L and the point rounded. This 
end was then hardened and polished. After an oil-hole had 
been let into the sleeve and the inside polished smooth, the fixt- 
ure was finished. 

As the manner of finishing the formed surface of the work is 




FIG. 219. 

distinctly different from tne usual methods in general use, and 
as the forming-tool and holder are of a novel design, they are 
worthy of a detailed description. 

By referring to Figs. 219 and 220, in which a plan and side 
view respectively of the tool and holder are shown, the following 




FIG. 220. 

description of them will be intelligently understood. The holder 
is a casting of the shape shown at F, and was dovetailed on the 
bottom and fitted to the cross-slide of the screw-machine and 
equipped with a rack to mesh with the feed-gear, as shown at 
N, Fig. 218. The portion for holding the forming-tool Q, Fig. 



INTERCHANGEABLE MANUFACTURING. 199 

219, was then planed dovetail, slanting upward to tbe degree 
shown in the side view of Fig. 220. A hole was then drilled 
and tapped through the lug R to admit the tool adjusting-screw 
,SL Two headless set -screws T T were also let into the side, as 
shown. The forniiug-tool Q was of f -iiieh flat tool steel, finished 
all over, and fitted to the holder as shown. The shape required 
was then worked out on the face for its entire length, and finished 
in the milling- machine with a special fly-cutter, as shown in Fig. 
218. The cutting-face of the tool, T' V, Fig. 219. was sheared 
off to the angle shown, so as to allow the work to be cut gradu- 
ally. The tool was then hardened and drawn to a light -straw 
temper, and the cutting-face ground and oil-stoned to a keen 
edge. The fixture and tools were now complete and ready for 
work. 

The parts were set up in the screw-machine in the relative 
positions shown in Fig. 218. The machine was started, and the 
driver-lever pulled back, thereby drawing the driver I into the 
chuck. The work was then placed on the centres, with the por- 
tion C on the chuck-centres and the face end on the running-cen- 
tre K. The driver-lever was then pulled out, causing the driver 
1 to emerge and drive the work, the running-centre L travelling 
vvith it. The handle O of the cross-slide was then pulled down 
and the forming-tool presented to the work, cutting the face 
gradually. And as each portion of the work was reduced and 
finished, that point of the tool passed the centre and came out 
under the work ; and as the whole face was finished, the entire 
cutting-face of the tool passed free and clear of the work. The 
driver 1 was then drawn in (without stopping the machine) and 
the tail-centre drawn back and the work removed. Another cast- 
ing was then located on the centres, the driver sent out, and the 
work finished as before. 

As will at once be seen, the use of the special chuck reduces 
the time necessary to locate the work on the centres, and remove 
it when finished, to the minimum. And the running tail-centre 
eliminates the possibility of the work running hot and burring, 
as well as the waste of time in adjusting the centre against the 
work. The methods of finishing formed surfaces by means of 
tools of the design shown is meeting with more favor all the 



200 TOOL-MAKING AND 

time, as very wide and intricate forms cau be duplicated on 
round work without any trouble. Another thing, by the use of 
this tool work can be finished, one piece in exact duplication of 
the other. 

FIXTURES FOE FORMING PIECES OF IRREGULAR 

OUTLINE. 

In the preceding chapter a fixture for forming pieces of ir- 
regular outline from the bar was described, which fixture was 
adapted to work having considerable stock to be removed. The 
tool here to be described consists of a similar fixture for use in 
the screw-machine for forming irregularly shaped surfaces, but 
from individual castings instead of from the bar, and in which 
less metal is to be removed. 

The article for which this device was used is an improved gas- 
stove cock made in two parts, each of which is of irregular exte- 
rior outline, as shown in the longitudinal sectional view in Fig. 




221. The length of the assembled cock over all is 4f inches, 
and the pieces are composition castings with the holes K and F 
cored in them. Certain preliminary minor operations are neces- 
sary on both parts 1 and 2 before the forming-cutter is used, in 
order to form the threaded hub C C on part 1 and the threaded 
recess J5 B in part 2 for a means of definitely locating them on 
the face-plate, which operations will be described later on. 

The forming-cutter used for obtaining the irregular outline 
surface is one of the circular forming type of cutters, which is 
shaped entirely around its exterior surface, the cutting-edge 
being produced by milling out a longitudinal groove on its exte- 
rior as shown in Figs. 222 and 228. This is the type of cutter 
that may be ground and reground almost indefinitely without al- 



INTERCHANGEABLE MANUFACTURING. 



201 



teriug the shape of its cutting-edge if the body of the cutter is 
properly shaped. The cutter shown in Figs. 222 and 223, which 
represent the cutter used for machining the surface of part 2 of 
the gas-cock, was made of tool steel, which was annealed and 




FIG. 



bored out at D and a key way let down through the entire length 
at C, after which it was driven on to an arbor and the ends fin- 
ished as shown at B B, and the required shape turned on to the 
outside from end to end to templet, as shown. The finishing of 




FIG. 223. 



this forming was done very carefully by first roughing it out with 
the usual lathe-tools and then using a variety of hand-tools to 
finish it to shape. Especial care was taken to get its entire sur 
face smooth and free from marks, and it was finished to a dead- 



202 



TOOL-MAKING AND 



smooth finish by means of lapping with stick, emery, and oil. 
This was necessary, as the work was required to have a high fin- 
ish after being machined, and as the manner in which the cutter 
was presented to the work allowed of its burnishing the same as 
soon as the cutting-edge had removed the required amount of 
stock and passed the centre. 

After being lapped, the cutter was set up in the milling-ma- 
chine and a groove milled out to form the cutting -edge from E G 




FIG. 224. 

to F, as shown in Fig. 222, it being milled on a spiral, as shown 
in the face view, Fig. 222, so as to cause the cutter to remove the 
stock progressively. In fact, the cutting-edge of the cutter was 
finished in the same manner as a wide-face milling-cutter, except 
that the spiral was not quite as abrupt. After finishing the cut- 




FiG. 225. 

ting-edge as shown, the cutter was carefully hardened and drawn 
to a very light-straw temper, thus leaving it as hard as is con- 
sistent with reliable cutting. 

The cutting-edge was then ground on the cutter-grinder, and 
carefully oil-stoned so as to present a smooth, keen edge for its 
entire length. The holder, or bracket, shown in Fig. 223, which 
supports the cutter and its cutter-stud H, Fig. 225, was made 
from a forging with the shank N finished to fit the large tool-post 
of the turret-lathe. The way in which the cutter is mounted in 
the holder is shown in Fig. 223, which shows a top view of the 



INTERCHANGEABLE MANUFACTURING. 203 

cutter in place upon its stud H and the hand-lever R mounted 
upon the projecting end M of the stud. 

The manner of using the fixture may be understood from Figs. 




FIG. 226. 



226 and 227 ; Fig. 226 showing a front view of both fixture and 
work in position, the face-plate, the turret-head, and Fig. 227 an 




FIG. 227. 



end view toward the face-plate to indicate the manner in which the 
cutting-edge of the cutter is presented to the work. In machin- 
ing the work the handle of the cross -slide is moved by the left 



204 



TOOL-MAKING AND 



hand of the operator until the cutting-edge of the tool is in the 
position against the work shown in the end view, Fig. 227, and 
held there with the help of the feed-screw of the cross-slide, 
while with the right the lever of the forming-tool is pulled for- 
ward. As the cutter is slowly revolved in the holder by the 
pressure on the lever, it cuts and removes the required amount 
of stock progressively, due to its spiral cutting-edge, and as the 
cutting-edge passes the centre line the friction of the finished por- 
tions of the work revolving rapidly against the exterior of the 
cutter produces a high finish of its entire surface. 

The cutter which was used for milling part 1 of the gas-cock, 
Fig. 221, is shown in front view and section in Figs. 228 and 229, 
and in end view in Fig. 224. This 
cutter was made, tempered and 

CUTTER 





FIG. 228. 



FIG. 229. 



ground exactly the same as was the other, and its method of 
use in removing the stock and obtaining the burnish or polish is 
identical. 

In connection with the finishing of these gas-stove cocks other 



Q 




FIG. 230. 



fixtures were used which may be of interest. In forming the 
threaded hub C C, parti, Fig. 221, a pair of slip-jaws for a regu- 



INTERCHANGEABLE MANUFACTURING. 



205 



lar two- jaw chuck was used for chucking the work while ma- 
chining. These jaws, which are shown in Fig. 230, are of cast- 
iron ; are finished dovetail to drive into the jaws proper of the 
chuck, and are located in the proper relative positions by means 
of a taper-pin at R. The way in which these jaws are con- 
structed and finished to allow of locating the work as shown is 

evident from the sketch. The facing 
of the surface M M is accomplished by 
means of. a hollow mill, which differs 





FIG. 231. 



FIG. 232. 



from "the type generally used in that it has fifteen teeth. The 
hub C C is finished by the mill also, the thread being cut by 
means of a collapsible die. 

In Figs. 231 and 232 are shown the slip -jaws which are 
used for the first and third operations on part 2, Fig. 221, which 




FIG. 233. 



contains the gas-cock proper. These two sets of jaws are con- 
structed similar to the first set, Fig. 230, and are used in the 
same way. The part shown at A, Fig. 232, is for holding the 
casting for part 2 while the surface at A A is being faced, the 



206 



TOOL-MAKING AND 



seat for the rubber washer let in at D I), and the hole at B bored 
and tapped to fit the threaded hub, part 1. The other set of 
jaws is used for holding part 2 after being machined all over, 
when the taper hole for the key J is being let in at 8, Fig. 231, 
which shows the work located within the jaws and the hole 




FIG. 34. 

drilled at 8. This hole, after being centred in the usual man- 
ner, is reamed to the required taper by means of a "floating" 
reamer of the usual type. 

For turning the washer-seat at D D, in part 2, the special ec- 
centric box-tool shown in Fig. 233 was used, which is of an inter- 
esting construction. A is a holder or frame, made of cast-iron, 
which a shank portion at B turned to fit the hole in the turret. 
C is an eccentric bushing located within the holder by the set- 
screw H; G the cutting-tool ; F the lever by which it is manipu- 
lated. The depth of cut is regulated by adjusting the lever stop- 



INTERCHANGEABLE MANUFACTURING. 207 

screw J, which is let into the projecting lug K as shown in the 
end view of the tool. In using this fixture, after the tool G has 
been entered into the cored hole in the work the required dis- 
tance, the lever Fis raised slowly until it rests against the stop- 
screw J, which determines the proper depth of cut, then it is 
dropped and the tool backed out. 

A novel drill- jig was designed for use in boring the six in- 
clined air-draught holes leading into the combining-chamber F 
in part 2 of the gas-cock. The jig is shown in plan and in 
sectional elevation in Fig. 234, with the work in place. As is 
shown, these six holes are required to be drilled at an angle with 
the axis of the casting, and also to be equidistant, and an inter- 
esting design is the result. A is the body casting of the jig, 
which is machined on the base at Z>, and also 011 both sides of 
the projection B, to an angle T with the base, as shown. The 
indexing-device X and the locating-stud for the work are of tool 
steel, hardened and ground. There are six equally spaced 
notches in the index-plate which coincide in shape with the end 
// of the index-pin R and locate the work for the six different 
holes. The drill-bushing P is located as shown in the swing-lid 
J, which is hinged within the two sides K K of the body casting 
A by means of the pipe L. A hole in the lid allows clearance 
for the work when located in the jig; all that is necessary for 
removal being to swing the bushing-lid J back and unscrew the 
work off the locating-stud. 



CHAPTER XIV. 

The Construction and Use of Boring Fixtures and 
Similar Tools. 

THE DKILL-PRESS AND BOEING FIXTURES. 



ONE of the things that make the large drill -press a valuable 
machine tool is its adaptability for performing accurate opera- 
tions in the production of interchangeable parts by the use of 
simple and often inexpensive fixtures. In fact, I do not hesitate 
to state that it runs the turret-lathe a close second for the place 
of the most rapid and economical producer in the shop. 

Now aside from the adaptability of the drill-press for jig- 
drilling, there is any quantity and variety of work requiring to 
A A 



c/x 




FIG. 235. 

be bored which can be handled to good advantage on this ma- 
chine; and in this chapter, among other things, I will devote 
considerable space to describing and illustrating types for bor- 
ing-fixtures which were designed to be used on the drill-press 
and have worked well in practice, and their presentation will 

208 



INTERCHANGEABLE MANUFACTURING. 



209 



prove suggestive for others. The practical points for the design- 
ing and construction of the fixtures will assist the tool -maker in 
the attainment of the desired results with ease, and dispense 
with much unnecessary labor and expense. 

BORING AND FACING FIXTURE FOR "SEXTIT" 

CASTINGS. 

The casting shown in sketch Fig. 235 has six radiating cylin- 
ders, each with a cored hole through it. It was necessary to 
bore and finish the holes in line with the central hole E, and the 




opposite holes in line with each other. The jig shown in Figs. 
236, 237, and 238 was made for the job. 

The centre hole was first bored and counterbored, and the 
front faced at I). ' It was then driven on to an arbor and the 
back faced at F. 

The jig consists of an angle casting with a boss, faced on the 
back at // and I respectively, also a back extension on the top. 
After being planed on the bottom and dovetailed for the bush- 
ing-plate K, bosses H and L were faced and the top was planed 
and dovetailed for the upper bushing-plate J. It w^as also dove- 
tailed on the side for the index-pin bracket W, and the hole 
bored for the clamping- stud 0. 

The two bushing-plates K and J, of machine steel, were fitted 

tightly into the dovetailed channels, located in line with each 
14 



210 



TOOL-MAKING AND 



other, and fastened. The, centres of the holes for the bushings 
Z7and Fwere located by setting the casting on its side on a sur- 
face-plate and striking a line from the centre of the hole for 
the stud O to the plate J and K with the help of a Brown & 
Sharpe height-gauge. The centre in the opposite direction, the 
distance from the face of the boss H to the centre of the bushings 
U and V was also marked. The plates J and K were then 





Front of Jig-Without the Work 
V 



FIG. 237. 

driven out and the holes were bored and the two bushings U and 
V were made and forced in. The plates were then returned to 
their respective positions. 

The index-plate N and clamping-stud are in one piece. It 
was a mild -steel forging. The plate had on its periphery six 
equidistant square notches. The index- pin bracket TF, a cast- 
ing, was then fitted to drive tightly into the dovetailed channel 
in the side of the angle -plate. The hole for pin X was then 
bored. 

The pin was made of tool steel, the end fitting the square 
notches in the index-plate, and slightly rounded to enter the 
notches easily. A stiff helical spring V was made and also a 



INTERCHANGEABLE MANUFACTURING. 



211 



hole was drilled in the pin X for the spring cross-pin. After 
the handle Z was made all the parts were assembled. 

All that remained to complete the rig was the boring-bar, Fig. 




FIG. 238. 



239, and the two sets of cutters B B and D. This bar 
was of machine steel, turned taper at the end to fit the 
drill-press spindle, and for the rest of the length a run- 
ning fit in the bushings U and V. The bar was small 
enough to clear the cored holes. Two sets of cutters 
were made, one set for roughing and the other for finish- 
ing. These cutters were fastened in the bar by taper- 
keys. The jig was strapped to the table of a large 
drill-press. The index-plate N, with the pin X in one 
of the notches, was clamped and a casting to be bored 
clamped in position on it, so that the boring-bar would 
be as nearly central as possible in the cylinder to be 
bored. The roughing -cutters were then fastened in the 
bar and the holes were bored. These cutters were then 
removed and the finishing pair were substituted and the 
holes were finished. 

After all six holes were bored, which required only three ad- 
justments of the index-plate, both ends of all six cylinders were 
faced by using the cutters D. All the eastings, of which there 



c 

B 



FIG. 239. 



212 



TOOL-MAKING- AND 



were a large number, were bored and faced in this manner, and 
were found, when assembled with other parts, to interchange per- 
fectly. 



DRILL-PRESS BOEING 



RIG FOB INTERCHANGEABLE 
WORK. 



The tools described in the following were used for boring and 
finishing the cast-iron shell shown at B, Figs. 242-243. The part 
finished is shown at F, being a seat for a brass ring that was to 
fit in snugly so as to be air-tight, and it was also necessary to 
have them all exactly the same size. The shells were being made 
in lots of five hundred. 

The jig for holding the shells is also shown in the two views. 
A is the jig, of cast-iron, which was faced off on the bottom and 





FIG. 240. 



FIG. 241. 



strapped true on the face-plate of the lathe by the ears E E. It 
was then bored out to the shape and size of the shells at C and a 
hole bored in the bottom for the plug D. It was then milled out 
at three places on the top to give the three wings D clearance. 
The plug D, made of machine steel, was then turned and finished 
so as to just fit the inside of the shells, as shown, and then driven 
into the jig A, projecting through at the bottom, as shown. The 
part projecting through just fitted the centre hole in the table of 
the large drill-press in which the boring was done. 

Figs. 240 and 241 show the holder and tools for boring, which 
were made in the following manner: G is the holder proper, 
made of cast-iron with three wings, to allow of using three cut 



INTERCHANGEABLE MANUFACTURING. 



213 



ting-tools, as we found after experiment that this number worked 
the best. The tool was first chucked and the hole J bored and 
reamed for the shank J. It was then removed and the shank J 
turned and finished to fit the spindle of the drill -press, with a 
shoulder at M. The other end was turned down so as to drive 




snugly into the holder G. The assembled tool was then put be- 
tween centres in the milling-machine and the holes for the tools 
K K If were laid out and drilled and reamed. It was then taken 
out and the holes for the set-screws L L L were drilled and 




FIG. 243. 

tapped. Next, the three cutting-tools were made and finished as 
shown. These were hardened and drawn, and inserted in their 
places, which completed the boring-tool. 

A piece of steel the size of the hole in the table was chucked 
in the drill-press and inserted in the hole in the table, which was 



214 TOOL-MAKING AND 

locked, thereby setting it true with the spindle. The jig A was 
strapped on the table by the ears E E, with the lug D in the 
centre hole, and the work put in, resting on the bottom as shown 
in the sketch. The plug D centred it and the three pins not 
shown entered the holes in the ears B, which prevented it from 
truing. The holder, Fig. 240 was then set into the spindle and 
the tools set to cut exactly the right diameter, and after being run 
down to the proper depth the spindle-stop was set. 

The rest was plain sailing and, except for stopping to sharpen 
tools at long intervals, the pieces were turned out very rapidly 
(each and every one alike) at a very small cost and much better 
and cheaper than they could have been done by any other prac- 
tical means. The saving in the first one hundred shells paid for 
the cost of the tools. 

A SPECIAL MACHINE FOE BOEING BEACKETS AND 
SPINDLE-HEADS. 

When constructing sensitive drill- presses of from one to five 
spindles, the boring of the hole for the spindle in the upper- 
bracket and the spindle-head is done after all the other work has 
been done and the upper column, upper bracket, and spindle - 
head assembled. In the following, Figs. 244 to 247, I show and 
describe a machine which was designed specially for doing this 
work that is, for boring the spindle holes in drills of from one 
to five spindles. 

As this tool or machine is designed to be used and fastened 
directly to the columns while the holes are being bored, the pos- 
sibility of error in the alignment of the spindle when assembled 
is reduced to a minimum ; also, the manner of locating and fast- 
ening the tool to the work while in operation is as reliable and 
positive as could very well be devised for the class of work for 
which it is used. The tool consists of, first, a body casting K of 
the shape and design shown in Figs. 244, 245, and 246. The 
driving-spindle Y, with a tight and a loose pulley, TFand W TT 
respectively, at one end, and a bevel-gear V at the other. In 
the head Q is the spindle-driving gear with the two driving- 
pins R E ; is the spindle or cutter-bar, and S the bar-driver, 



INTERCHANGEABLE MANUFACTURING. 



215 



while H is the means for feeding the pinion, which engages the 
rack, 011 the bar or spindle. The sets M M M M in the lugs 
which project above the face of the plate or body casting shown, 
are for bracing and holding securely the brackets and heads 





while they are being 
bored. PP, in the spin- 
dle 0, are the cutters, 
while the adjustable 
angle pieces J J, and 
the clamping-levers L L, 
are for fastening the rig 
true and positively to 
the columns while in operation. 

The means and ways called 
into use in the construction and 
successful operation of the boring 
rig are of interest and they will 
be described in turn. After the 
body casting A was secured, the 
first thing done was to bore and 
finish the hole through the head 
B and the tail 0. The size of the 
hole in the head B is shown clearly 
in the detail drawing in Fig. 247. 
The boring was accomplished by 
strapping the casting lengthwise 

on an angle-plate, which, in turn, was fastened to the table of the 
large drill-press first drilling a clearance-hole through both 
head and tail large enough to allow of the boring-bar (used for fin- 
ishing), being entered through both the head B and the tail C, get- 



FlG. 244. 



216 



TOOL-MAKING AND 



ting them approximately central in each. A bushing which just 
fitted the hole in the centre of the drill-press table, and within 
which the bar would fit snugly, was then tapped in and located in 
the table. This was for strengthening and centring the boring- 
bar. The bar and cutters were then centred, the table clamped 
in position, when the holes were bored 
and finished to size required in each. The 
front of the head B was then faced, by 
using a cutter of sufficient width. 

We were now ready to plane off the 
base. This was done by first securing two 
" V" blocks, with a tongue on the bottom 
of each, by which they were set dead cen- 
tral to each other (by entering the tongue 
into the central slot in -the planer bed), 
and a piece of turned steel long enough 
to extend about six inches outside of each 
of the holes bored, and to fit each of them 
snugly. The casting was then set, and 
secured by resting the bar on the " V" 
blocks, and clamping and casting at either 
end. This made the alignment of the hole 
at a true right angle with the planer-head. 
The base of the casting A was then planed 
perfectly flat for its entire length, as far 
as the lugs or extensions F F, which were 
planed to the angle shown at G, or the 
same as that of the columns on which it 
was to be used. The distance from the 
centre of the hole in the head J5 and the 
tail C to the extreme point of the planed 
angle at G was exactly one-half of the 
width of the dovetailed slide of the columns. This done, the 
casting is removed from the planer and reset on the drill-press 
by strapping to an angle-plate, and the hole bored in D for the 
driving-shaft 1^, care being taken to get it at right angles and 
central with the hole in the head and tail, and the necessary dis- 
tance from it, to allow of the two bevel-gears (7 and Q meshing 




FIG. 245. 



INTERCHANGEABLE MANUFACTURING. 217 

correctly. This hole is bored sufficiently large to allow of a 
machine-steel bushing V being driven in to act as a bearing. 
The hole for the rack-pinion in the bosses E E is also bored and 




FIG. 246. 

finished, to the size required at each end, in this setting, boring 
the large part deep enough to allow of the pinion being in- 
serted therein. The casting is then removed and the holes 
drilled and tapped for the four set-screws M, and also the slots 
for the adjusting- and clamping-levers L L let in at K K, as 
shown. 

The driving-shaft Y was then made and finished, as shown ; 
as were the two pulleys W and W W. The gear U is keyed on 
and the collar X keeps the loose pulley W Win position. This 




FIG. 247. 



being done, we were ready to finish the construction of the head r 
and spindle or boring-bar. This is clearly shown in the cross- 



218 TOOIs-MAKING AND 

sectional drawing in Fig. 247. The first thing done was to 
finish the spindle or boring-bar 0. This was turned, as will be 
seen, with a collar at (2) to rest against, and also threaded for 
the two jam-nuts (5). The rack (4) is fastened to the centre of 
the sleeve by letting it into a channel ^-iuch deep in the sleeve. 
The large shoulder-bushing is then made, and is first bored and 
finished to the same diameter as sleeve (3), after which it is 
placed on a mandrel and turned to the shape 011 the outside, as 
shown, there being two shoulders, one to rest against the face 
of the head B and the other to rest within the counterbored 
portion of the gear, the smallest diameter fitting the hole in the 
head B tightly, the projecting end of the portion being threaded 
for the two jam-nuts N N. The turning of the shoulders, as 
shown, allows of easily locating the gear Q; which revolves free 
around the outside of the bushing. 

It is now necessary to plane the channel (10) through the 
entire length of the bushing, as a clearance -way for the rack (4). 
This is done as shown, breaking completely through the bush- 
ing for the length of its smaller diameter, and to the same depth 
in its larger diameter, the stock left here being sufficient to 
hold and keep the bushing from expanding or warping from its 
original shape. Two holes are drilled in the face of the gear Q 
to admit the driving-pins R R, which are made, as shown, 
rounded on the ends, and driven tightly into the gear. The 
driver 8 is then made of cast-iron and bored to fit the boring- 
bar or spindle 0, as shown, being counterbored on the face to 
a depth and diameter sufficient to clear the jam-nuts ,7 and the 
sleeve 3. A key is then let into 8 at (8), which fits freely the 
keyway Tin the spindle. The two holes (6) (6) coincide with 
the pins*.R R in the gear Q. The pinion (11) and shaft or stud 
(12) are finished in one piece, the stud fitting the smaller hole 
in E and the pinion resting against the counterbored back of the 
large one. The stud is threaded at one end for the adjusting- 
nuts shown at 1 1 in the other three views. 

All parts of the head being complete, they are assembled as 
shown in Fig. 247, which allows of the spindle being inserted 
and withdrawn freely. After the clamping-levers L L, Figs. 
244, 245, and 246, and the angular clamps JJ are finished and 



INTERCHANGEABLE MANUFACTURING. 219 

fastened, all the parts are assembled as shown in the plan view, 
Fig. 244, and the slots for the cutters P P let into the bar or 
spindle O in the position shown, at right angles to each other. 
The rig is now ready for work. 

The column, with the bracket and heads in position, is laid 
flat on its back 011 the bench, and the boring rig (with the spindle 
slipped out) placed on the first column, and fastened at G, Fig. 
244, by means of the two clamps J, to the dovetailed surface of 
it. The head of the bracket and the spindle-head to be bored 
project up through the openings in the centre of the body cast- 
ing or base A. The boring-bar or spindle is then entered 
through the head of the rig, and through the cored holes in the 
bracket and, head, and allowed to project slightly through the 
tail C. The set-screws M at each side of the bracket-head and 
spindle-head are then screwed up, and adjusted to hold the heads 
perfectly rigid while they are being bored. The cutters P P 
are then entered and fastened within the bar, as shown, and the 
driving belt shifted from 1 the loose to the tight pulley. The driver 
8 is then slid up, until the two pins R R in the gear Q have en- 
tered the hole in it. The spindle or boring-bar is then revolving 
at the proper rate of speed, and is fed in by grasping the handle 
through the part H, the pinion of which engages the rack, on 
the sleeve of the spindle. The spindle is fed in until the holes 
are bored, when it is fed back, and the driver 8 pulled out and 
the cutters removed, and another set for finishing inserted instead, 
when the operation is repeated. When the bracket and spindle- 
head of the first column are finished, the rig is removed and 
clamped to the next one, when the operation of boring and finish- 
ing is repeated, and so on, until all four heads and brackets have 
been bored and finished to size. 

As can be seen, the design and construction of this boring rig 
allows of its use in the boring and finishing of the heads and 
brackets of all sensitive drills of from one to six or more spin- 
dles ; when the same design and construction is maintained in 
each. It also allows of being operated by comparatively un- 
skilled help, without the possibility of spoiling the parts ma- 
chined by it. Its construction is simple enough to satisfy the 
most exacting ; while the fact that it is located while in opera- 



220 



TOOL-MAKING AND 



tion directly on the columns, adds to the positiveness and accu- 
racy of the work produced ; as it does also allow of the inter- 
changing of the parts machined. 

BORIXG DKILL-PBESS TABLES. 

On the one-spindle drills, instead of the sliding table used, on 
the others, a flat swinging table and a small round one are sub- 
stituted. The flat table shown at A, Fig. 248, after being 
planed on all sides is required to be bored at F to fit the turned 
part on the top of the column on which it swings. For finishing 
this hole which was cored a fixture for use in the drill-press 
was designed, and also a cutter-holder. The fixture, as shown in 
Fig. 249, consists of a flat casting with two raised surfaces at 
B B on which the table rests, and the four lugs, G C and 1) D 




FIG. 248. 

for the locating-points. This casting, after being machined on 
the back, is finished on the face by first planing the raised sur- 
faces B B, and then taking a cut down the front of the lugs 
C C and D D so as to get them at right angles to each other. 
The centre for the hole for the bushing E is then laid out and 
located so as to be central with the table sidewise and the proper 
distance from the end of the other. The hole is then bored and 
reamed to size required. The bushing E is then made and 
hardened, and lapped and ground to size required; then forced 
tightly into the hole as shown. Holes are then drilled and coun- 
terbored at the back for the clamping-bolts, G G. The two 
straps are of machine steel and are bent at right angles at one 
end, as shown. The straps are finished to a height sufficient to 
allow of their clamping the table securely. 

The cutters and holder are shown in Fig. 249, and as will be 
seen it is a plain holder with two rows of cutters set within it. 



INTERCHANGEABLE MANUFACTURING. 221 

The holder K is of cast-iron which is first centred and turned 
taper at one end to fit the drill-press spindle, as shown, and at 
the other end, J, to fit the bushing E in the fixture. The largest 
portion, K, is turned to a diameter sufficiently small to allow the 
cutters to project out T 5 of an inch. The holes for the cutters 
were drilled by setting the holder on centres in the universal 
milling-machine and indexing for five, then the first row of holes 
L drilled. The second row was then drilled in the same man- 
ner, \ of an inch higher up at M and so that each hole would 
come between two of the first row. The cutters were made of 
Stub steel f -inch in diameter, and were finished at one end for 
the cutting-edge, as shown. They were then set so that the first 




FIG. 249. 

row L would rough out the hole, and the second row of five cut- 
ters M finish it. They were held tightly in position by means 
of set- screws, as shown. 

When in use the fixture was strapped on the table of the large 
drill -press, in the position shown in Fig. 249, by means of a bolt 
through each end, at II. The cutter-holder was then adjusted 
so that the stem J of holder would be in line with and enter 
freely the bushing E. The table to be bored was then strapped 
in position on the fixture A, locating it squarely against the lugs 
C C and D D, as shown. The stem J of the cutter-holder was 
then entered into the bushing E and the feed thrown in and the 



222 TOOL-MAKING AND 

hole bored and finished to size. This is the best way of finish- 
ing large holes in flat surfaces of the kind shown ; the fixture 
being both reliable and simple in construction, as well as rapid 
in operation. The cutters in the holder K should be left as hard 
as possible, without danger of cracking, so as to allow of finish- 
ing the maximum number of holes without the necessity of fre- 
quent removal and grinding. 

MACHINING ROUND TABLES. 

In Fig. 250 is shown two views of the round table as used for 
the small presses. This table is in two parts N, the table proper 
of cast-iron, and 0, the stem of cold-rolled mild steel. The man- 
ner of finishing the tables is as follows : The casting is first 
chucked in the turret-lathe and the hole bored and reamed for 
the stem; reaming it about 0.003 less than the diameter of the 
stem 0. The stems are simply cut off from the bar in the screw- 
machine, and slightly chamfered at each end. The tables are 
then heated in a gas- muffler to a dark red, 
when the stems are inserted so as to project 
slightly above the face. This way of fastening 
the stems is the best, as it is both rapid and 
permanent. After the tables have cooled suf- 
ficiently to allow of being handled, they are 
faced and the rini turned by holding them by 
the stems in the universal chuck in the lathe. 
They are then transferred to the grinder, where 
the face is ground. This gives it a neat and 
mechanical appearance, as well as finishes the 
face perfectly flat. 

The finishing of flat surfaces by grinding, as in the above 
case, is far preferable and more expedient than the one usually 
employed that is, taking finishing cuts in the lathe, which is 
an obsolete way of doing it and very slow, especially when a per- 
fectly flat surface is required on the finished work. 

FINISHING CUP CENTRES. 

In finishing the cup centres shown in Fig. 251 they are first 
turned on the stem P to the same diameter as the table stems. 




INTERCHANGEABLE MANUFACTURING. 223 

They are then fastened by the stems in a nose-chuck in the lathe 
and the inside turned to a sixty degree angle by using the com- 
pound rest, and a special holder in which self -hardening steel- 
cutter is fastened. 



ADVANTAGES IN THE USE OF SPECIAL TOOLS. 

In this chapter, and those preceding it, the number and 
variety of tools and fixtures which have been shown and de- 
scribed for the duplication of parts have been suffi- 
cient to fully demonstrate the advantages to be gained 
in manufacturing by the use of special tools as com- 
pared with the old methods. Also, it may be well 
to mention that the use of such tools eliminates the 
necessity of the results attained in the work de- 
pending on the skill and intelligence of the work- 
men, and allows of employing less expensive help 
in the manufacturing of various parts. While the 
tools shown in this chapter are the simplest and least expen- 
sive of their class, if by the study of them they will be 
the means of converting some of "the-old-way-is-good-enough- 
for-me" sort of shops, to the adoption of the system of inter- 
changeable manufacturing, they will have more than served their 
purpose. 




CHAPTER XV. 

Design, Manufacture, and Use of Milling-Cutters. 
MILLING-CUTTERS CLASSIFIED. 

IT goes without saying that the king of all modern cutting- 
tools is the milling-cutter ; for that reason it cannot be too fine a 
piece of workmanship. Of what use would be the plain or uni- 
versal milling-machine without it? In fact, when considering 
milling -cutters it is well to remember that the milling-machine 
was created for it and that all the genius and excellent workman- 
ship put into these wonderful machines are for no other pur- 
pose than to rigidly hold and revolve the cutter or cutters at the 
proper speed, and to feed the work to it at a rate suited to the 
material being milled and the type of cutter doing the work. 

Milling-cutters may be classified in four distinct types. The 
first and probably the most common form is known as the axial, 





FIG. 252. 



FIG. 253. 



Fig. 252, in which the surface cut is parallel to the axis of the 
cutter. This cutter has teeth on its periphery only ; these may 
be straight or spiral teeth. Cutters of this character, made in 
appropriate widths, are used very much for milling broad, flat 
surfaces and for cutting key ways in shafts. For deep cuts, or 
for slitting metal, they are made of large diameter and thin. 
These are called metal -slitting saws, and are ground hollow on 

the sides for clearance. 

224 



INTERCHANGEABLE MANUFACTURING. 225 

The second class of cutters is known as the radial, Fig. 253, 
in which the surface cut is perpendicular to the axis of the cut- 
ter. These cutters are called radial because their teeth are used 
in a plane parallel to the radius of the cutter. End-mills, face- 
mills, butt-cutters, etc., are all tools in this class. 

The third class of cutters is the angular, Figs. 254 and 255, 
in which the surface cut is neither parallel nor perpendicular to 




FIG. 254. FIG. 255. FIG, 256. 

the axis of the cutter, but is at some angle with this axis. Fre- 
quently cutters are made with two different angular cutting edges, 
in which case the angle is marked on each side, as in Fig. 255. 

The fourth class of cutters is the formed cutter, as shown in 
Fig. 256. The cutting-edge of this class is of an irregular out- 
line. When properly backed off, these cutters can be ground 
and retain their original form. Gear-cutters, tools for grooving 
taps, etc. , are all classed as form cutters. 

Among the numerous engravings in this chapter will be 
found illustrations of a large number of cutters which are used 
in milling-machines. In most cases it is advisable to use a cut- 
ter of small diameter rather than of large diameter. Cutters 
from 1-J- to 2 inches in diameter are the most economical for gen- 
eral milling. 

THE DESIGN AND MANUFACTURE OF MILLING- 
CUTTEES. 

It is conceded to-day that one of the chief factors in bring- 
ing the process of milling into universal use and to the front 
15 



226 TOOL-MAKING AND 

rank of machine operations, was the introduction of the emery 
wheel for grinding milling-cutters. 

So much attention has now been given to the milling process, 
that in many cases a degree of perfection has been attained which 
apparently leaves little room for improvement. It is still true, 
however, that even in up-to-date shops the output is below what 
it might be. Some firms undoubtedly have developed milling 
far beyond the rest of the country, but as a whole there is no 
reason why milling should not continue to advance during the 
present decade as much as it did in the past one. It should 
advance not only in becoming more general and more widely 
applied but also in the direction of giving better results. 

STANDARD STYLES AND SIZES OF CUTTER 

It is now quite a common practice to use cutters which are 
not adapted to their work. The number of standard styles and 
sizes of cutters is already enormous, and neither the manufac- 
turer nor the user can contemplate with equanimity the idea of 
a large increase, and yet the existing standards are inadequate 
for the great variety of work they have to perform. The ordi- 
nary standard cutter is intended to be used on cast- or wrought- 
iron, steel, or brass, and the recognized form has been evolved 
as the best compromise for varied work. 

There are many special operations where the cutter passes 
through different metals at the same time, or through mica, or 
raw-hide or paper, or where any curious conditions arise ; and 
the best form of cutter can only be arrived at by experiment on 
that particular operation. For an individual job it matters little 
that a cutter is not the very best design, but with repetition work 
it is serious to use a tool which is not capable of giving the best 
results. 

UNDERCUT TEETH. 

A turning or planing tool for iron or steel has top rake, as 
well as clearance below, and milling -cutters for many operations 
should have similar rake. From experiments, and from general 
experience, it has been demonstrated that undercut teeth may 



INTERCHANGEABLE MANUFACTURING. 



227 




often be used with advantage under the following conditions : 
The machine should be powerful, and the cutter-arbor of ample 
size. The pitch of the teeth should be so coarse that only two 
or three may cut at the same time. The speed of cutting should 
be slow, and the feed sufficiently quick to allow each tooth to 
take a real cut. When these con- 
ditions cannot be fulfilled, there 
will probably be no advantage in 
departing from the usual form of 
tooth. 

Slotting- or grooving -cutters, 
spiral cutters, and side -mills are 
well adapted for undercut teeth. 
Formed cutters may be so made, 
but there is a difficulty with the 
form. Thus, in Fig. 257 if the true form required is made along 
the cutting face A B, the cutter will leave a false form to the line 
A C. The difference is in most cases very slight, and always may 
be allowed for in making the cutter, but variations in grinding 
the face will alter the form. It is easy in grinding them to see 
when the faces are radial, but it is not so simple to give a known 
amount of rake. 

END-MILLS. 

The question of undercut teeth also arises in the case of end- 
mills. Three methods of cutting the teeth are shown in Figs. 
258, 259, and 260. Fig. 258 shows an ordinary spiral end-mill 



FIG. 257. 





FIG. 258. 



FIG. 259. 



with right-hand teeth and left-hand spiral, by which arrangement 
the pressure from the work always tends to push the cutter into 
its socket. This is the correct form if the cutter is to be used 
for milling on the sides, if, strictly speaking, it is not to be 
used as an end-mill, for which it is unsuitable, because the 
teeth on the end have negative clearance and would not cut 



-o 

OF THE 

UNIVERSITY 




228 TOOL-MAKING AND 

freely. For end -cutting, the ordinary straight teeth shown in 
Fig. 259 are more suitable, and in some cases a right-hand cutter 
with a left-hand spiral would be best of all (see Fig. 260). This 




FIG. 260. 

gives correct clearance to the end teeth, and when used under 
favorable conditions such a cutter has no more tendency to leave 
its socket than a twist-drill, which is made on exactly the same 
principle. 

SIDE CLEAEANCE. 

Standard Cutters frequently give trouble in the matter of side 
clearance. It is assumed that the cutter must not lose its width 
on resharpening, but there must be some dishing on the sides, or 
it would be unworkable ; accordingly a very slight clearance is 
given, say one-half degree each side, which will cause the cutter 
to become two-thousandths (0.002) thinner when ^-inchhas been 
ground away in diameter. The cutter would be more service- 
able if it had, say, one degree clearance each side, but that would 
cause it to lose its width too soon. Now suppose a quantity of 
work is required where the width of groove is not particular to 
one-fiftieth (0.02) of an inch, or where the cutter is only used for 
roughing, it would be worth while to take a standard cutter and 
grind extra clearance on it. This is particularly the case when 
cutting brass, which is very liable to bind on the sides. 

INSEETED TOOTH-CUTTEES. 

The time has now arrived when a great development should 
take place in the direction of cutters with inserted teeth. The 
obvious advantages are : 

1. That cheap material may be used for the body of the cut- 
ter, and the very best high-speed cutting-steel for the blades. 

2. Hardening difficulties are reduced to a minimum. 

3. When worn out the blades may be replaced at a small ex- 
pense. 



INTERCHANGEABLE MANUFACTURING. 



229 



The great objection is the first cost, particularly in the case 
of cutters less than about seven-inch diameter. Also inserted 
blades are usually not very suitable for wide cuts. The supe- 
riority of the inserted tooth-cutter is most unquestionable in the 
case of side- or straddle -mills which are mainly cutting on the 
corners. 

One widely used method of holding the blades is shown in 
Fig. 261. The blade A is ground on the sides. The bush B is 
turned parallel and has a flat milled on it at an angle with the 

X 




FIG. 361. 

centre line. This bush, which fits in a recess, as shown, is sim- 
ply a wedge and is knocked in. There is a screw C to prevent 
it coming loose. A second screw D, a patent one, is shown for 
adjusting the blades side wise. There seems to be no reason why 
these cutters should not largely displace solid side-mills except 
in the smaller sizes. 



LIMITS OF rNTACCUBACY. 

Coming now to the manufacture in quantities of cutters, the 
great principle of "good enough " asserts itself. It must first be 
determined exactly what "good enough" is, and the drawing 
must show that exactly. Any time spent in making a measure- 
ment nearer to a dead size than is called for is a loss. Fig. 262 
is a working drawing of a simple cutter which is to be measured 
with the micrometer, and not with limit-gauges. 

According to this drawing, it has been determined that if 
error in the thickness of a ^-inch cutter does not exceed one- 
thousandth (0.001) of an inch, it is good enough. This is clearly 
shown, and the grinder must adhere to the limits given, but must 



230 



TOOL-MAKING AND 



not waste time iu making every ^-inch cutter to within one-half 

thousandth (0.0005) of the nominal size. 

Again, it has been found that about one-hundredth (0.01) is 

a reasonable allowance for cleaning out the turning marks on 

the sides after hardening. It is, how- 
ever, quicker to grind off a few extra 
thousandths than to turn them off, 
and the lathesman must keep within 
the limits ten to fifteen thousandths 
above ^-inch. %\\%%. He has 110 ex- 
cuse for leaving too much or too lit- 
tle for grinding, nor yet for wasting 
time by taking a cut of two thou- 
sandths (0.002) off the side. 

It is shown that the actual diam- 
eter is not important, and the lathes- 
man has a limit of one-hundredth 
(0.01) of an inch, which means that 
the grinder must just clean out the 
turning marks. 

The drawing shows that the side 

recesses may vary in diameter by one-tenth (0.1) of an inch. 

The clearance each side is stated as one-half degree, and it is 

essential that this shall run out to the extreme tips of the teeth. 

USE A:NT> ABUSE OF CUTTEES. 

A whole chapter might well be devoted to the use, abuse, and 
maintenance of milling cutters. A slignt reference only can 
be made to this branch in a chapter dealing mainly with their 
design and manufacture. 

It is a source of great satisfaction to the maker that when a 
cutter is broken by being run backwards on to the work, the 
breakage is characteristic. A cutter may be taken that has been 
spoilt in this way, and although the man who broke it will be 
absolutely sure that it ran in the right direction, the cracks 
down the faces of the teeth tell a different story. 

On many operations it is of the first importance to have a 
full flood of lubricant ; a trickle is not sufficient. 




INTERCHANGEABLE MANUFACTURING. 231 



EEGEIKDING. 

It cannot be too strongly insisted that it is very wasteful to 
use a dull cutter. It is as hopeless to mill successfully without 
adequate grinding arrangements as it would be to turn satisfac- 
torily with only the door-step to sharpen the tools on. When a 
cutter is changed in time, the sharpening should only occupy a 
very few minutes for most small sizes. If run too long, the 
grinding becomes a serious operation, which causes the grinder 
to lose his temper, and to draw the temper of the cutter. 

When the resharpening cannot be accomplished by two or 
three passes over the emery wheel, the cutter should be mounted 
on a mandrel and ground whilst revolving until the worn part 
has all been removed ; and the tooth-by-tooth grinding should 
be reserved for backing off to give the cutting edge. Not only 
is this much the quicker way, but there is no risk of drawing the 
temper if ordinary care be exercised. 

It must always be remembered that however good a cutter is, 
the cutting-edge may be so damaged by a little carelessness in 
grinding as to receive any degree of injury up to the point of 
being ruined. It is well to touch the cutting-edge with an oil- 
stone after grinding. 

As the teeth are usually regrouud on a dry wheel, it is impor- 
tant that arrangement should be made for exhausting the dust 
produced. Dry grinding is now recognized as a dangerous occu- 
pation, causing lung diseases. The operation is not capable of 
imparting consumption itself, but it so irritates the throat and 
lungs as to keep them in an unhealthy condition and- render them 
susceptible to consumption germs. For this reason the emery 
wheel should be enclosed, as far as possible, in a hood, and a 
good exhaust provided by a fan or other suitable means. 

QUALITY OF STEEL TO USE FOE MILLING- 
CUTTEES. 

The all -import ant question of the quality of steel to be used 
is too often ignored. Self-evident as it is, the fact may yet be 
overlooked that two cutters, one made of the best steel and 



232 TOOL-MAKING AND 

one of the worst, may be identical in appearance, and the differ- 
ence will only become apparent in use. 

In small or complicated cutters, in which the cost of steel is 
only a small proportion of the total cost, the amount saved by 
using cheap steel is- slight. 

In large cutters of simple forms with little machining on 
them, where the cost of steel is perhaps one-third or even one- 
half the cost of the finished cutter, the saving effected by using a 
poorer quality of steel amounts to a great deal, and may recon- 
cile the user to an inferior cutting edge. Good steel may be re- 
cut, and after the hardening the cutter should not be perceptibly 
inferior to a new one. 

SELECTING A SET OF CUTTEES FOE A MILLING- 
MACHINE. 

A person buying a milling-machine for general use, who has 
not had previous experience, is immediately confronted with the 
problem of cutters, and the questions are frequently asked, " What 
should I buy for a starter? " and "What is likely to be required 
for my work f " It is to this class that these suggestions are 
offered rather than to those who by years of experience and 
study are prepared to give counsel and are not in need of what 
I have to offer. 

To begin with, do not under any circumstances buy up a lot 
of second-hand cutters because they can be had at a bargain, as 
they are liable to prove very expensive in the end for many rea- 
sons. They may be unsuited for the work, out of date in design, 
and will unconsciously be copied in the new cutters that are 
made, or they may be worn away so that further grinding is im- 
possible and consequently useless. 

AN ASSOETMENT OF MILLING-CUTTEES. 

The assortment of cutters shown in Fig. 263 makes a good set 
to put with the new milling-machine. A wide range of work 
can be done with them, including the making of new cutters of 
almost any style or size. This set consists of two of No. 6 and 
one mill arbor, suitable for shell -end mills from 2 to 5 inches 



INTERCHANGEABLE MANUFACTURING. 



233 



in diameter, and No. 7 illustrates an end-mill 2-J inches in diam- 
eter to fit it. The arbor has a threaded collar with tongues to fit 
in the slots milled in the back end of the cutter for driving it. 

The screw tapped into front end of the arbor drops into the 
counterbore in the cutter, thus keeping out of the way of the 




chips and holding the cutter in place. Figs. 264 and 265 show 
two other styles of end-mills and arbors, each having something 
to recommend them. The cutters shown in the group at the 
right are tapped standard, and have a slot milled across the 
back end to fit the loose collar, which is used to force off the cut- 
ter and serve no other purpose. If desired, the cutter itself 
could be extended and milled to fit a wrench, the only objection 
being that the cutter would be slightly more expensive. 

The arbor shown with cutters to fit in Fig. 264 has No. 10 
B. & S. taper to fit in the machine, No. 4 Morse taper in front 




FIG. 264. 



FIG. 265. 



to fit the cutters, and Woodruff key to do the driving. It has a 
nut to force the cutter off and a screw to hold it on, the same as 
the screw in No. 1 of Fig. 263. 

These three styles of arbors and cutters are excellent and any 
one of them, will give good results. The threaded cutter is the 



234 TOOL-MAKING AND 

cheapest because it does not require internal grinding or lap- 
ping. The taper-arbor and its cutter are perhaps slightly more 
expensive to make, because it is necessary that the cutter be 
ground internally to fit the taper. This is to be recommended 
when the most accurate work is required. 

SHELL END-MILLS. 

Shell end -mills are very useful cutters and will be largely 
used wherever a milling-machine is supplied with them. 

Small end-mills should be made solid, perferably with taper- 
shanks (Nos. 3 and 4, Fig. 263), as the most accurate and satis- 
factory way to hold them. 

SPINDLE SURF ACE-MILLS. 

The spindle surface-mill (No. 5, Fig. 263) is 2-J- inches in 
diameter, 3 inches face, and is one of a great variety listed by 
the cutter manufacturers whose practice is to make with straight 




FIG: 266. 

teeth where the face is less than f -inch wide. This style of cut- 
ter, in widths to suit, is commonly used for key-seating. 

Cutters with side teeth (No. 6) could be used for key -seating, 
but it is obvious that they would fall below size much sooner 
than the cutter with outside teeth. 

Teeth milled spiral will do better work on wide cuts than 



INTERCHANGEABLE MANUFACTURING. 235 

when milled straight, on account of the shearing out, and for 
heavy roughing the teeth should be nicked by cutting a coarse 
thread around the blank before milling the teeth. 

The side -cutter is most useful in pairs for milling both sides 
of a piece at once, like squaring a tap -shank ; the cutters oper- 
ating on opposite sides of the piece take away any tendency to 
spring and produce accurate work rapidly. 

GANG-MILLS AND INTEELOCKING CUTTEES. 

A gang of spiral surf ace -cutters with side teeth, the inner pair 
made interlocking, is shown in Fig. 266. The teeth are cut 
spiral, right and left hand alternately, to balance any side-thrust 
and to give top rake to the side teeth doing the cutting. The 
inner pair are made with clutch teeth to interlock ; the bearing- 
faces being scooped out to allow the clutch teeth to engage. 
Paper is used to extend the cutter as the sides are ground away, 
maintaining a constant size and insuring interchangeability. 
The same cutters can also be used for roughing and finishing by 
taking out some of the packing while roughing, and restoring 
the cutters to the proper width before taking the finishing cut. 

Fig. 266 shows a group of common forms. Care should be 
taken in grinding to have the face of the teeth radial; the ten- 
dency is to grind the point more than the base of the tooth, which 
places the cutting-edge at a great disadvantage. 

Generally it is more economical to buy standard cutters from 
the maker, and in many instances special ones also, but it is at 
times desirable to do some of this work at home, being cheaper 
if the tool-room is properly equipped and organized, and the 
educational advantage of such work has a distinct value. 

MAKING CUTTEES. 

For making cutters, Nos. 10, 11, and 12 of Fig. 263 provide 
a good outfit. The first two have sixty degree angles, one right 
and one left hand, and will suffice for most straight tooth work. 
No. 12 is for milling spiral cutters and has twelve degree angles 
on one side and forty degree on the other. 

Practice has shown that it is best to make cutters with radial 



Of THE 

UNIVERSITY 

OF 



236 TOOL-MAKING AND 

teeth. If they are undercut so as to give the cutting-edge top- 
rake, as in a lathe-tool, it makes a weak tooth liable to break 
easily, but adds to the efficiency of heavy ones. 

There is far more danger of getting too many teeth than too 
few into a cutter. 

If the cutter is small in diameter so that it will become too 
thin if the teeth are deep, take the first cut through at the proper 
depth and then mill around again after revolving the work so as 
to bring the proper angle. 

MOST VITAL POINT IN MILLING-MACHINE 
PEACTICE. 

The most vital point in milling-machine practice is that cut- 
ters of whatever design be kept sharp. A dull cutter is like 
any other tool that is dull its efficiency is greatly reduced, the 
work produced is inferior, and the cutter wears rapidly away. 

The same principle applies to the cutting-edge of the milling- 
cutter as to any other cutting-tool for metal. If too little clear- 
ance is ground it will not cut well, and if too much, it will chat- 
ter ; about three degrees will generally give good results. 

SPEEDS AND FEEDS FOE MILLING-CUTTEES. 

A subject upon which too much cannot be written nor 
thought given is that of proper speeds and feeds for milling- 
cutters. Often the question is asked: "What inle is there for 
determining the proper speeds of cutters. " When a direct an- 
swer is not given to this question, the questioner is always dis- 
satisfied and usually discouraged. Of course there is no "hard 
and fast " rule for determining the proper feeds and speeds of 
cutters, and in this book one cannot be given. The texture and 
hardness of the material to be machined determines the surface 
speed in each case. Thus, for cast-iron, a speed of forty feet 
per minute may be safely taken as a good basis when taking 
heavy roughing cuts, while for light finishing cuts on the same 
material, (after the scale has been removed) fifty feet per minute 
is not too fast. When working steel twenty feet per minute is 



INTERCHANGEABLE MANUFACTURING. 237 

not too fast, and for brass sixty feet per minute is a good basis 
for determining the correct cutting speeds for these metals. 

Although the hardness and texture of the material worked 
upon is the chief factor to be considered when determining mill- 
ing speeds, the nature of the cut and the shape are also very im- 
portant factors. Thus, for instance, a large slitting-saw can be 
run about twice as fast as a large surf ace -cutter when working 
on the same material. 

K"ow, with regard to the rate of feeds for milling, the most 
advanced practice is to take a roughing-cut with the fastest feeds 
the machine will pull ; that is, provided the cutter is relatively 
as strong in comparison as the machine in which it is used. If 
the nature of the work requires a cutter of such a form as to be 
comparatively weak, it is often better economy to break an occa- 
sional cutter than to allow the machine to work at a slow rate of 
speed. 

When running a cutter at a slow rate of speed and advancing 
it at a fast rate of feed 011 cast-iron, compressed air, delivered to 
the cutter with sufficient force to clear away all chips as fast as 




FIG. 267. 

they are produced, will prolong the life of the cutter, even when 
the fastest feeds are fed against it. When working steel, a 
stream of oil on the cutter will have the same effect, providing 
the oil is delivered under pressure sufficient to wash away the 
chips entirely from the cutter. 

In regard to " burning " cutters, or drawing the temper while 
working them, it must be understood that this will not happen 
through too fast a feed, but it is always to be traced to too high 
speeds. Thus, when both speed and feed are up to the maxi- 
mum, the actual rate of table travel per minute can be further 



238 TOOL-MAKING 

increased by reducing the speed of the cutter and increasing the 
feed rate. 

When taking finishing cuts, the rate of speed depends upon 
the quality and degree of finish required. Here it may be 
stated that experiments have determined that 0.030 per revolu- 
tion of a 3|-iuch cutter when surface-milling leaves a good fin- 
ish, and in machine work will leave a surface that will require 
little scraping to make a good bearing. 

Fig. 267 shows a collection of forming cutters. 

To succeed with milling-cutters they should be made right, 
hardened properly, sharpened regularly, and speeded and fed 
properly. 

SUGGESTIONS FOE MILLING. 

Experience in the use of milling-cutters will teach anyone 
that unnecessary expense and annoyance may be avoided by fre- 
quent and proper grinding of milling-cutters. A dull mill will 
not do good work and wears away very rapidly. At the first 
appearance of dullness, use your cutter-grinder, it will save 
your cutters, your time, and your patience, and will enable the 
cutters to do their best and most rapid work. 

In order to preserve the correct shape of formed corners, 
grind the teeth radially. 

No definite rule can be given for speed or feed of cutters, but 
the usual tendency in all classes of work, except for finishing 
cuts, is for slow speeds and coarse feeds. 

For cutting wrought-irou or steel use lard, oil, or some one of 
the usual compounds manufactured for this purpose. 

Small mills on horizontal millers will cut better and faster 
than larger mills; they also cost less and will last longer. 

Wherever possible use a mill that is wider than the cut to be 
taken. 



CHAPTER XVI. 

The Hardening and Tempering of Milling-Cutters. 
HARDENING. 

ALTHOUGH the quality of steel used for milling-cutters is of 
great importance the proper hardening of it is equally so. It is 
a fact that bad steel well treated will make better cutters than 
good steel poorly treated. The hardeners of such tools cannot 
complain of a lack of literature, as treatises and articles on the 
subject are continually appearing. However, practice alone can 
teach the details and refinements of the most interesting process 
in the making of milling-cutters. 

In the following, methods are put forward for the proper 
hardening of milling cutters which are the result of experience, 
and while they are not necessarily the best, it is claimed that 
they have brought success when used. 

It pays to spend time on filling blind holes, sharp internal 
angles, etc. , with clay. In many cases asbestos should be used 
with wire over a weak place, or over a part which must be kept 
soft. The furnaces should be in a partially darkened room 
from which direct sunshine is excluded. 

Though I have never found any disadvantage in using cold 
water for quenching, it is quite reasonable to suppose that water 
containing a considerable amount of air dissolved in it may not 
cool the cutter so uniformly as it would do if the air had been 
expelled, and therefore boiled water is to be preferred. 

After machining, tools should have a few days rest before 
hardening. If they must be hardened immediately, they should 
be annealed first, but care must be taken to prevent a tendency 
for the surface to become decarbonized. To accomplish this, ah 
excess of charcoal should be kept near the cutters in the furnace 

to maintain a reducing atmosphere. 

239 



240 TOOL-MAKING AND 



HEATING. 

It is not only necessary that the cutter should be at the right 
heat, and at a uniform heat, when plunged, but it must have 
reached that heat gradually and uniformly. If the heat be applied 
gradually, the cutter may be made hotter than the correct tem- 
perature, and yet not crack. If a crack appear under these cir- 
cumstances, it will probably go through the cutter. If a cutter, 
after being heated too rapidly, or allowed to get much, too hot, 
be carefully brought to the right temperature in the furnace and 
then plunged, the teeth may clink off. They are certain to do 
so if it be not nearly uniform in' temperature at the time of 
plunging. In case of a mistake in heating, a cutter should be 
allowed to cool out, and heated fresh. 

PLUKGI:N T G. 

. The manner of plunging is worth attention. A thin cutter 
should be in a vertical plane when it enters the water. If it 
were plunged horizontally, one side would be cooled before the 
other, and would cause the cutter to warp. A cutter with a long 
hole should be plunged into the bath with the hole vertical, to 
allow the water to circulate freely. Cutters with large recesses 
should be plunged with the recess uppermost to allow the steam 
to escape. The object generally is, in the first place, to cool 
symmetrical parts simultaneously ; and, secondly, to let the water 
have free access to every part without delay. Thus a long thin 
reamer should obviously be dipped endwise, in order that all 
the flutes may cool simultaneously, notwithstanding the fact 
that the water would come into contact with every part in a 
shorter time if it were dipped horizontally. 

Cutters need not be cooled right out in the water. They may 
be removed as soon as they are so far chilled that the temper 
color would barely show if they were polished immediately. 
Cutters of a few pounds weight may be lifted from the water as 
soon as the teeth are chilled. In a few minutes the heat from 
the inside begins to reheat the teeth, and just before the color 
shows they must be plunged again for a second or two. This 



INTERCHANGEABLE MANUFACTURING. 241 

may be repeated three or four times or more, according to the 
size of the cutters. When at last they are cool enough, they 
should be maintained for a few minutes at a heat sufficient to 
just show color a light straw and then allowed to cool out in 
the air. In order to see the color, it will be necessary to have 
another piece with a clean surface for comparison. 

WAEPING. 

Change in shape in hardening may be largely prevented by 
previous annealing, by keeping to the very lowest temperature 
that will give sufficient hardness, and by the utmost uniformity 
of heat in every part. 

LEAD BATH. 

Long thin reamers may be uniformly heated in red-hot lead. 
It is, however, important, in order to prevent the lead from 
being cooled by the immersion of cold articles, and also to a^oid 
injury to the articles themselves by too sudden heating, that 
reamers or other articles should be independently heated to a 
red just below the hardening temperature, and the lead bath 
should be reserved for the final heating, the lead should be that 
sold as " chemically pure, 77 and when in use there should be a 
great abundance of small charcoal floating on the surface to pre- 
vent the formation of dross which would cling to the teeth. 

DEGREE OF HAEDNESS. 

Whether heated in lead or not, the teeth of a finished cutter 
should be as hard as a good, new, smooth file. They should 
scratch glass. 

INJUEY IN HAEDEKING. 

It has been stated above that steel may be overheated, and 
yet not crack if the heat be very uniform. This point must be 
strongly insisted upon, and claims careful attention. It means 
that we must not regard breakage as a dividing point between 
good and bad hardening. It is the division between bad and 
worse. When steel is badly treated, it will lose its best propor- 



242 TOOL-MAKING AND 

tioii long before the treatment is so very bad as to cause actual 
rupture. If in a large hardening a considerable quantity of tools 
are broken, it is probable that many of the remainder are as bad 
as they can be without actually breaking ; but if none are broken 
it is reasonable to assume that many are well hardened. A good 
hardener need not be afraid of occasionally getting a cutter 
barely hard enough or just doubtful in hardness, because a heat 
which accomplishes this will do the steel no harm, and it may be 
rehardened; meanwhile the operator has the satisfaction of 
knowing that the remainder of the day's work is probably very 
accurate indeed. 

There are then two extremes which are unquestionable. A 
cutter which on the one hand is not hard enough, or on the other 
hand is broken, evidently cannot be passed. 

TEST OF HAKDENING. 

As steel may be between these obvious limits and yet be 
damaged, a finer test is demanded, for if the hardener is to hit 
the exact point he must know exactly what success he has. 

SAND-BLASTING. 

For this purpose the following method has frequently been 
adopted with success. After being hardened and tempered in 
the usual manner, the cutters are dipped in oil and then sand- 
blasted. If there has been any overheating in the furnace, 
though not enough to do any apparent harm, cracks will appear 
on the faces of the teeth. These cracks, which are best seen im- 
mediately after sand-blasting, are frequently so small that they 
cannot be detected by ordinary means, and if the teeth are 
broken off the breakage will probably not follow them. A cut- 
ter on which the sand-blast reveals numerous cracks may still be 
quite passable indeed, it would have been considered perfect 
but for this test. Here is a means of trying the work of the 
hardener between narrower limits, and he has a warning that he 
is giving too much fire before a tool is spoilt. 

The sand-blasted cutter also possesses another advantage of 
some importance in the fact that if the temper be drawn in 



INTERCHANGEABLE MANUFACTURING. 243 

grinding sufficiently to cause any discoloration, the tell-tale line 
will show distinctly on the face of the tooth, and cannot be re- 
moved by another pass along the wheel. 

HEATING AND HARDENING LAEGE CUTTEES. 

The following method of getting a good uniform test on a 
large cutter, say about 9 inches diameter and 2-J- inches thick, in 
an ordinary blacksmith fire is over good, and if followed out 
carefully will result in perfect satisfaction. 

After getting a good deep fire, with plenty of well-coked 
blacksmith's coal as a foundation, and having the sides of the 
fire well banked up with fresh coal, the cutter should be placed 
in the fire and covered over with "live" coals of coke and the, 
whole brought up slowly until the cutter begins to show some 
red: 

Then place some dry pine boards, about one inch thick, over 
the top of the fire and almost entirely shut the blast off. The 
boards of course will take fire and soon become live coals. The 
cutter should then be turned over and a second layer of boards 
placed over the fire. 

By the time these are burned to good live coals we will have 
a thorough, uniform heat. Then after a slight application of 
the blast, so as to be sure to quench 011 a rising heat, and two or 
three turnings of the cutter in the fire, in order to keep the heat 
uniform, the cutter will be ready to quench. 

This may be done in "brine," allowing the tool to remain in 
the bath about fifty seconds. Then quickly withdraw it and 
place it in a tank of oil to finish cooling. The heating should 
take about thirty-five minutes. 

Although a good gas furnace should be used for such a job 
as the above, I realize that this is not always to be had when 
wanted. 

Finally, of hardening, it may be said that it is the most diffi- 
cult and the most interesting part of cutter-making. 



CHAPTER XVII. 

Drills and Drilling, Forming-Tools, Facing-Tools, 
Counterbores, Boring-Bars and Reamers. 

BOBING-BABS AND BEAMEBS. 

IN this chapter will be found much information, compiled 
from personal experience, the columns of technical journals and 
notebooks of fellow mechanics which will assist the tool-maker 
in the designing and constructing of any special small tools 
which may be required for special work in the line of drilling, 
counter- boring and boring. 

DEEP-HOLE DBILLING. 

* The process of drilling deep holes in metal is a familiar one 
in many shops, particularly where firearms are manufactured or 
heavy ordnance is constructed. Since the adoption of hollow 
spindles for lathes and other machine tools, the methods for 
machining the bores of guns have been employed in machine- 
tool shops for drilling these spindles ; and through this and the 
other means the principles of the operation have become better 
understood. It is not an easy matter, however, even with the 
best appliance, to drill or bore a deep hole, smooth and round, of 
exactly the required diameter from end to end, and perfectly 
straight. While many mechanics are familiar in a general way 
with the methods and tools for doing this work, some specific 
information upon the subject will be appreciated by those who 
have not had actual experience in deep -hole drilling. 

It is known that a long or deep hole that is, one long in 
proportion to its diameter is best roughed out and finished by 
using a tool on the end of a long bar, which enters the work 
from one end. This is true whether drilling into solid metal or 
boring and reaming a hole that has already been drilled or bored 

* "Machinery." 
244 



INTERCHANGEABLE MANUFACTURING. 



245 



out. A boring-bar which extends through the piece and on 
which is either a stationary or a travelling head, is not satisfac- 
tory for very long work, owing to the spring and deflection of 
the bar, which is made worse by the fact that the bar must be 
enough smaller than the bore to allow room for the cutter-head. 
While a long hole may sometimes be finished satisfactorily by 
means of such a boring-bar, by packing the cutter-head with 
wooden blocks which just fill the part of the bore that has been 
machined and so support the bar, the method is fundamentally 
wrong for long work. 

THE TWIST-DEILL. 

The modern twist- drill accomplishes all that is attained by 
the arrangement in Fig. 268, and in addition can be ground 




FIG. 268. 

without seriously affecting the rake, and will free itself from 
chips more readily, owing to its spiral flutes. The lands of a 
twist- drill present a large cylindrical surface to bear against the 
sides of the hole and take the side-thrust. If the drill is also 
guided by a hardened bushing, at the point where it enters the 



OIL PIPE FROM PUMP 
GLAND 



OIL AND 
CHIPS RETURN 
THROUGH PIPE 




FIG. 269. 



metal, as in the case of jig work, the drill will have very little 
chance to deflect and the hole will be accurately located and will 
be quite true and straight. 



246 TOOL-MAKING AND 

The twist-drill in modified form is also employed for deep 
hole drilling. The hollow drill shown in Fig. 268, and intro- 
duced by the Morse Twist-Drill Co., New Bedford, Mass., is 
adapted for this purpose, and in Fig. 269 is the arrangement rec- 
ommended by this company for feeding the drill into the work. 
The drill has a hole lengthwise through the shank, connecting 
with the grooves in the drill. The shank can be threaded and 
fitted to a metal tube which acts as a boring-bar and through 
which the chips and oil may pass from the point of the drill. 
Oil is conveyed to the point on the outside of the tube, as shown 
in Fig. 269. 

In using the hollow drill the hole is first started by means of 
a short drill of the size of hole desired, and drilled to a depth 
equal to the length of the hollow drill to be employed. The 
body of the hollow drill acts as a stuffing, compelling the oil to 
follow the grooves and the chips to fall out through the hollow 
shank. The methods of supporting and driving the work, and 
of feeding the drill, are clearly shown in Fig. 269. Drills of 
this type are regularly manufactured in sizes up to three inches 
in diameter by the Morse Twist-Drill Co. It is stated that the 
best results are obtained when drilling crucible steel by revolv- 
ing the drill twenty feet per minute, with a feed of 0. 0025-inch 
per revolution, while machine steel will admit of a speed of 
forty feet per minute, and a feed of 0.0035-inch per revolution. 

NUMBER OF CUTTING-EDGES DESIRABLE. 

When drilling a hole out of solid stock, some type of drill 
having two lips or cutting-edges is usually the most feasible, 
and probably nothing will be devised that on the whole surpasses 
the twist-drill for such work. An end-mill can be used for drill- 
ing if it has a " centre cut," and it will presently be explained 
how a tool with a single cutting -edge may be advantageously 
employed, particularly for deep-hole drilling. The familiar 
D -drill is of this type, and also its modification as used by Pratt 
& Whitney, in drilling gun -barrels. 

When it comes to truing up or enlarging a hole previously 
drilled or bored, the two-lip drill is not suitable in any of its 



INTERCHANGEABLE MANUFACTURING. 



247 



forms. For boring a true hole, nothing can surpass a single- 
pointed boring-tool, the ideal condition for finishing a hole being 
when the cutting-point is a real diamond, or a rotating wheel of 
abrasive material. 

It is obvious that when a hard or soft spot is encountered in 
boring with a tool having a -single cutting-edge, only that par- 
ticular place is affected by the spring of the tool ; while with a 




FIG. 270. 



FIG. 271. 



FIG. 272. 



FIG. 273. 



double-cutter, as shown in Fig. 270, any deflection due to irregu- 
larities, such as at a or b, will cause the tool to spring and the 
cutting-edge on the opposite side to introduce similar irregulari- 
ties in the opposite side of the hole. This is one objection to 
the two-lip drill for accurate work. 

With three points the tool is somewhat better supported when 
a high plac6 is countered, as at Fig. 271, and when a cutting- 
point strikes a low place, the other two edges are not moved 
away from their position so much, if they are opposite the first 
edge. Hence a tool with three edges should prove better than 
one with two, and one with four, Fig. 272, being better sup- 
ported, is better on this account than one with three, but has the 
disadvantage of opposite cutters. Five edges, Fig. 273, ought 
to give even better results. 

In general it may be said that in boring the best results are 
obtained when the tool has a single cutting-edge, but if it is de- 
sirable to have more cutting-edges, a tool with several will be 
more satisfactory than one with only two. Any machinist who 
has tried to true up the taper hole in a lathe-spindle, first by 
boring and then by reaming, will appreciate the superiority of 
the boring-tool over the multiblade reamer. A reamer some- 
times refuses to produce a perfectly round hole and will do this 



248 



TOOL-MAKING AND 



whether the number of teeth is odd or even, and this can only be 
prevented by spacing unequally or " staggering. " 

ADVANTAGES OF THE END-CUT. 

One trouble with reamers, however, is that the teeth neces- 
sarily cut on their side edges instead of on their ends, and the 
whole effect of any unevenness in the hole is to crowd the reamer 
to one side. The same condition exists to a less extent with a 
flat or twist-drill where the cutting-edges are at an angle with the 
centre line, and the resultant of any unusual pressure is felt 
partly as a side-thrust and partly as an end-thrust. Now, by 
making a drill to cut squarely on its end, and but very little or 
not at all on its sides, the side-thrust is mostly done away with. 

In Fig. 274 is a boring-tool, with a single cutting-edge, which 
cuts on its end and is capable of drilling a true hole in solid 
metal. It was illustrated in the August, 1896, number of "Ma- 
chinery. 77 It consists of a round, tool-steel bar, with one end 
flattened and ground to form a cutting-edge, as shown. It is de- 
signed to be held in the tool-post of the lathe, in a position per- 




FIG. 274. 

pendicular to the face-plate. The inner edge, or corner of the 
cutting-edge, should be. slightly rounded, to help support the 
cutter and prevent chattering, and the width A of the cutting - 
edge should be from ^- to T V -iueh less than the radius of the 
hole to be drilled. 



INTERCHANGEABLE MANUFACTURING. 



249 



DEILLING DEEP HOLES BY THE PEATT & 
WHITNEY METHOD. 

A highly satisfactory drill for use in drilling deep holes is 
one brought out by the Pratt & Whitney Co., principally for use 
in connection with their gun-barrel drilling-machines. The tool 
in question is a development of the old D or "hognose" drill, 




FIG. 275. 

which has one cutting-lip only. It is carefully ground on the 
outside and is supplied with an oil-duct through which oil at 
high pressure may be brought direct to cutting-edge. Eef erring 
to Fig. 275, A is the cutting-edge, B the oil-duct, C the chip- 
groove. 

In the milling the latter groove is brought directly to the 
centre, so that in this respect the drill is very free-cutting as 
compared with the ordinary two-lip twist-drill, which has a cen- 
tral web. In the end view the shape of the chip-groove is clearly 
indicated. The cutting-edge A is radial and the bottom of the 
groove touches the centre line x y. 

In sharpening the drill the high point, or part first entering 
the work, is not in the centre, as is usually the case in drills, but 
as per Fig. 275, in which D is a cross.- section of work being 
drilled and E the high point of drill. Grinding the drill in this 
manner is one of the reasons for its running true or straight, the 
teat F on the work acting as a support to the drill, which, owing 
to its periphery being partly relieved, would have a tendency to 
travel in a curve away from its cutting-side. The piece being 
drilled is run at very high speed, the periphery speed at the outer 
diameter of the hole running as high as 130 feet per minute on 
machine steel. The feed, however, is quite fine. 



250 



TOOL-MAKING AND 



These tools are made of high-grade steel and left very hard, 
so that the fine feed has- little tendency to glaze the cutting-edge. 

In practice, the piece being drilled is held and revolved at 
one end by a suitable chuck on the live spindle of the machine, 
while the other end, which should be turned perfectly true, runs 
in a stationary bushing having at its outer end a hole of the di- 





ameter of the drill. -The drill enters the work through the bush- 
ing and is thus started perfectly true. See Fig. 276, in which A 
represents the chuck, B the work, C the bushing, D the support 
for holding the bushing, E the drill. 

Through the oil -duct of the drill oil is forced at a pressure 
varying with its diameter from one hundred and fifty to two 
hundred pounds per square inch. After passing the cutting- 
edge the oil returns to the reservoir by the chip -groove <7, Fig. 
275, forcing chips along in its travel." In drills of large diame- 
ter, especially when working on tough, stringy material, the cut- 
ting-edge is usually ground so as to produce a number of shav- 






CR06S-6KTtORATA-, 



ings, instead of one the full width of the cutting-lip, so that no 
trouble is experienced in getting the chips out of the way. The 
oil, of course, is used over and over again, and with a large res- 
ervoir will be kept quite cool. 

The drill is made up of the drill -tip and shank, the tip vary- 
ing in length from four inches to eight inches, while the length 
of shank is determined by the depth of hole that is to be drilled. 
Fig. 277 will clearly illustrate the construction of a small, com- 
plete drill, A being the tip, C the shank, and D the oil -duct. 



INTERCHANGEABLE MANUFACTURING. 251 

The shanks on small drills are made from steel tubing rolled as 
per cross-section a a. The tip is carefully fitted and soldered to 
the shank, which, it should be noted, is a little smaller in diameter 
than the tip. The shank, with oil under pressure, is very stiff. 

The relief or clearance to the cutting-edge of the drill, the 
amount of " high-point " of the drill should be off centre, and 
the number of rings on the end of the drill depend entirely upon 
the material that is to be drilled. For instance, on very soft 




FIG. 2T8 

stock the supporting rest should be more substantial than on 
hard spindle or gun steel, so that it is evident that on soft stock 
the high point should be off centre, or much nearer to the outer 
diameter than on hard stock. 

Fig. 278 is a sketch of a 3-inch drill, and the reader will ob- 
tain a very clear idea from same of the appearance of the tool 
we have described. This figure illustrates a drill ground on the 
end so as to produce several shavings. 

BOEING HOLLOW SPINDLES WITH A HOLLOW 

DEILL. 

* In boring the inner tubes of steel guns of large calibre, it 
has long been the practice to bore them with a hollow drill, 

* " American Machinist. " 



252 



TOOL-MAKING AND 



which 
moved 



leaves 
is not 



a core in the centre, so that the entire metal re- 
converted into chips, but only what might be 
termed a shell of it, the outside diameter of this 
shell being practically equal to the bore and the 
inner diameter being enough smaller to leave a 
reasonable thickness for the drill. 

At the works of Schneider & Co. , at Cruesot, 
France, gun tubes are bored on this plan, and it is 
likely that the same plan is followed at Krupp's. 
It has not, so far as known, however, been ap- 
plied to the boring of hollow spindles for ma- 
chine tools until very recently, when it was found 
in use in the shops of Mr. Dietz in Cincinnati, 
Mr. Dietz 's shop being operated in connection 
with that of the Lodge & Shipley Machine Tool 
Company, and upon certain sizes of their lathes. 
Mr. Dietz uses in a boring- machine of the usual 
type a drill made like the sketch, Fig. 279, 
which is a hollow cylinder with a T 3 7 -inch pipe 
for lubrication, and the cutter is located as shown, 
inclined somewhat to the axial plane in order 
to give a top rake and with the edge gashed in 
order to break up the chips and allow them 
to be washed out through the groove from one 
end, and then reversed and the boring completed 
from the other end. This leaves a core of metal 
which, as "it is worth a considerable amount, is 
well worth saving, to say nothing of the fact 
that the boring is more easily done and with less 
strain upon the machine by this plan than where 
all the metal is reduced to chips. 

DEILL NOTES. 



As a rule, the cutting-edges of twist-drills 
are formed with a cutter of correct form to pro- 
duce a radial line of cutting-edge ; thus a different form of cutter 
is required for milling the flutes of straight- flute drills. 




FIG. 279. 



INTERCHANGEABLE MANUFACTURING. 253 

Drills are generally made of 0.002-inch or 0.993-inch taper 
per foot for clearance, and have the major part of land on the 
periphery ground away for the same purpose, about 0.003-inch 
on a side. 

Drills for brass should be made with straight flutes ; those for 
cast-iron and tool steel should in those cases have spiral flutes at 
an angle of about sixteen degrees ; soft steel, twenty-two degrees. 

Chuckiug-drills, for use on cored holes, or as followers of 
solid twist-drills, are quite often provided with from three to 
eight flutes ; the latter, on large work, are very efficient. Care 
should be taken, in grinding, to insure all teeth cutting simulta- 
neously. These tools are made of solid, shell, and inserted type. 

The inserted type are preferable for straight flutes over 2f 
inches, and for angular flutes over 4 inches, on account of cost. 

For drilling a large hole in a spindle the latter should be sup- 
ported in a back rest, and the drill entered through a drill-bush- 
ing to start perfectly true. Then, by using a drill with one cut- 
ting-edge and ground on the outside, a long, straight hole may 
be readily produced. An ordinary twist-drill will do practically 
the same if the centre is made female, the only objection being 
that this form is much more difficult to grind. 

CIRCULAR FORMING-TOOLS. 

Circular forming-tools for machine steel and cast- iron should 
have a generous amount of clearance. 

Care must be taken on particular forms, when forming-cut- 
ters are not on centre, that they are formed with this point taken 
into consideration. 

Circular threading -tools for inside threading must be much 
smaller than the work ; about one-third is the proper practice. 

Care should be exercised to use a correct angle of chaser. 

PLAIN FORMING-TOOLS. 

Plain forming tools should have a clearance of from six and 
one-half to ten degrees. 

Rake : Machine steel, eight to thirteen degrees. 
Rake: Tool-steel, medium, six to nine degrees. 
Rake: Brass, none. 



254 TOOL-MAKING AND 

The clearance on tools for brass is quite often stoned off its 
cutting-edge to prevent "biting in" (due to ease in cutting) and 
then chattering (due to great thickness of chip and consequent 
difficulty in severing). The "stoning off" also tends to act as a 
support for the cutter. 

FACING. 

For steel and cast-iron, cutters with from six to twelve de- 
grees rake cut very freely, The clearance should be from three 
and one-third to ten degrees ; when there is any tendency to chat- 
ter, the cutting-edge should be oil-stoned on clearance-face suffi- 
ciently to prevent " biting in." On very broad work it often 
becomes necessary to make cutters without any rake or mngle, 
but allow scraping, to prevent chatter. 

In practice it is found advantageous to place cutter ahead of 
centre, exposing a larger cutting-edge to work, giving thinner 
chip. 

In multiple or inserted cutter-heads, it is well to unevenly 
space the cutters ; as a precaution against chattering, have the 
cutters "staggered." 

Use machines with large bearings, and with chucks close to 
same, for good results. 

COUNTEEBOEING. 

For cast-iron and steel, counterbores are generally made 
with ten to six teen -degree angles, i.e., spiral; for brass they are 
cut straight. Clearance is from five to ten degrees. On brass, 
"stone" the clearance -edge to prevent chattering. 

Counterbores internally lubricated are recommended for steel 
for use to depth of one -half of the diameter or more. 

Angle-clearance on all tools must be more than spiral gener- 
ated by feed at smallest diameter of cutting-point, plus suffi- 
cient to be really forced to work (about three degrees). 

COUNTEEBOEES. 

As a rule counterbores should be made with a hole chucked 
at the cutting-end several sizes below the hole that is to guide 
the counterboring tool. 



INTEECHANGEABLE MANUFACTURING. 255 

Then the guides used at the cutting-end may be of many sizes, 
asd fit many -sized holes. The shanks of the guides, or the ends 
that enter the holes, should be all of one size, and should be fitted 
to force lightly in so they may be readily removed from the body 
of the tool and others inserted in their place to fit a hole of an- 
other size. The upper portions of these guides are turned up to 
a shoulder, and to about half an inch or less from the outside, or 
according to the size of the tool. This also gives the workman a 
better chance to file the cutting-end or lips to a perfect and true 
edge. The lips on their sides may be an inch or less in length, 
according to tneir diameter, and they should be milled out 
diagonally in order to give a shaving cut and also a better clear- 
ance for the chips. 

BEAMING HOLES IN THE TUEEET-LATHE. 

To ream holes uniform in diameter in the turret-lathe or 
monitor, it is necessary that there shall be in all cases an equal 
amount of metal for the reamer to remove. To insure this con- 
dition two reamers, a rougher, and a finisher should be used. 
The hole, first, if cored, should be bored by a single or a double 
edge boring-tool to insure a hole comparatively true. 

BEAMING HOLES IN THIN DISKS. 

For reaming holes in thin disks a reamer of the "rose type" 
should be used, as it will "be self-supporting, and the possibility 
of enlarging the hole by its weight will be obviated. 

MACHINE-BEAMING WITH A " FLOATING 77 EEAMEE. 

Very often, when machine-reaming, the finishing reamer is 
supported loosely in its holder, and allowed to find its own centre 
'by following the true or concentric 

hole left by the preceding tools. /END OF REAMEI ^ 

This is usually done by having a 
" floating " reamer with a pin entered 
through the holder and the reamer 

in the back end, the hole in the reamer being made larger than 
the pin, thus allowing the reamer to find its own centre. The 
construction of a reamer of this type is shown in Fig. 280. 





256 TOOL-MAKING AND 

BEAMING TAPEB HOLES IK CAST-IKON. 

For reaming taper holes in cast-iron machine parts in the 
turret-lathe, particularly those parts from which large amounts 
of stock are to be removed, a reamer of the construction shown 
in Fig. 281 should be used. As will be seen, this reamer has 
only three blades. The flutes in a reamer of this kind should 
be cut as deep as the diameter of the stock will allow, and the 
blade should be given very little clearance. The clearance that 
is necessary may be provided by grinding the blades convex, as 
shown, instead of flat or hollow, as is usually done. When a 
considerable amount of stock is to be removed, a reamer of this 
type will work very well. The preliminary work re- 
quired, with regard to the other boring-tools, before 
the one shown should be used, consists of boring a 
hole to the right size for the small end of the reamer, 
after which the three-blade finishing reamer may 
be used to finish an irregular surface from three to six inches 
long, feeding the reamer in rapidly without danger of catching, 
chattering, or roughing up. In one large machine-manufactur- 
ing establishment thousands of holes are finished every day with 
reamers of this type, attaining the best results in the shortest 
time with the least trouble. 

TAPER^BEAMING IN THE SCEEW-MACHIKE. 

To do taper-reaming in the screw-machine, use reamers taper- 
ing from 2^ inches per foot upward, and the best results will be 
accomplished. For very accurate work the reamers will give 
better satisfaction if made with left-hand spiral flutes. 

For want of proper grinding facilities, however, this is not 
done in many shops. 

To ream slightly tapering holes of small diameters, the reamer 
should always be made with the teeth "staggered" in spacing, 
and each flute a left-hand spiral of different pitch. 

Very often roughing-, taper-, and forming-reamers for steel 
are finished with an undercut. They remove material very 
rapidly. 



INTERCHANGEABLE MANUFACTURING. 257 



EEAMEES FOE PEOJECTILES. 

In the production of projectiles, forming-, taper-, and curv- 
ing reamers are used. For this work roughing-reamers should 
be finished with a left-hand spiral thread nicked around, while 
the finishing ones should be finished straight. The finishing of 
taper-reamers with left-hand spiral flutes for this work prevents 
their being drawn in while cutting. 

TAPEE OF EOSE-EEAMEES. 

Eose-reamers should be given taper for clearance, about 
0.003-inch to the foot will be enough. This will prevent them 
from roughing up the hole and allow of finishing holes straight 
and correct in diameters. 

CENTEE-EEAMEES. 

Centre-reamers should be finished to an angle of sixty de- 
grees, and the work centres of all machines to the same. The 
centres should be hardened and ground in their machines by 
means of a good tool-post grinder to gauge, as it is impossible to 
do good work on defective centres. 

EEAMEES FOE BABBIT. 

For reaming babbit, the reamer may be of the usual form, 
except that the edges of the blades should be ground taper for 
about ^-inch from the end. Sometimes reamers for such mate- 
rial are finished with left-hand spiral flutes, which contributes 
to finishing a smooth hole free from lines and rings. 

EEAMING HOLES IN TWO KINDS OF METAL. 

Not infrequently it is necessary to bore a hole in a part which 
is made up of two kinds of metal, such as brass and cast-iron, 
for instance. This is a rather difficult thing to accomplish suc- 
cessfully, as the hole will usually be larger in the softer side of 

the metal than in the harder. However, by using a reamer with 
17 




258 TOOL-MAKING AND 

a cutter-face of the construction shown in Fig. 282, and cutting 
an uneven number of staggered flutes in it, satisfactory results 
will be attained. Have the angle of the cutter- 
face about ten degrees. In using this reamer, 
first bore the hole with the usual type of boring- 
FIG 382 tools until it is a size slightly below that re- 

quired, then chamfer the edges of the hole on 
the hard side and feed in the reamer, lubricating generously 
with oil, and always see that the hard side of the work is out. 

MACHINE-BEAMING OF BBASS PAETS. 

For the machine-reaming of brass parts some make their 
reamers slightly over size, but this is wrong. Instead, a reamer 
for brass should be ground in much the same manner as a turn- 
ing-tool for brass should be that is, in place of a radial line in 
the centre, as in most other reamers, the cutting-edges should be 
thrown off from the centre at an angle 
of about twenty degrees out of the radial 
line, as per Fig. 283. For the same rea- 
son, in turning brass, if the tool is ground 
straight and set central with the work, 
chattering is bound to occur. If, on the 
contrary, the tool is reground on top to 
an angle as described above, running toward the underside of 
the blade, chattering will be obviated and the tool will cut freely. 
Always keep the cutting-edges of reamers for brass as sharp 
as possible by "stoning," because as soon as the cutting-edges 
become slightly dulled they will bind and scream. 

SQUAEE EEAMEES AND EXPANSION EEAMEES. 

Fine finishing of holes in brass may be done with the square 
reamer or "scraper." Expansion reamers also possess many 
good points, but few, if any, can be expanded and adjusted for 
sizing without the cutting-edges requiring to be ground before 
the tool can be used. However, there are some in which the 
blades will expand equally. Even if it is necessary to grind the 
expansion reamers when changing an adjustment, there is econ- 




INTERCHANGEABLE MANUFACTURING. 259 

omy in their use when compared with the cost of a new solid 
reamer, especially when they are used for holes of large diame- 
ters. A long hole may be reamed straight by pulling back 
slightly after the reamer has commenced to cut. 

BEAMING SMALL HOLES. 

For machining very small holes in steel and cast-iron, ream- 
ers should be ground straight, while for brass and copper they 
should be ground slightly back, tapering in order to eliminate 
the possibility of roughing up the holes. 

Always remember that on reamers for steel and cast-iron the 
teeth should be 011 centre, while for brass, copper, and similar 
metals they should be at an angle of twenty degrees off the radial 
line. 

Speeds for machine-reaming should usually range from 20 to 
25 per cent, lower than turning and drilling-speeds. 

" HOME-MADE " BEAMEBS. 

There are in a great many shops numbers of "home-made" 
reamers in the possession of the men, made at various times by 
the mechanics, without due regard to their proper construction. 
Beamers of this kind should never be used for fine work, as they 
are usually defective. For instance, the flutes are too shallow 
and spaced too close, and often they are 
spaced evenly instead of being staggered, 
or they have an even number of teeth, all 
of which is wrong. When a reamer is FIG ^ 

evenly spaced it will chatter as soon as the 

cutting-edges fall into the notches left by the preceding one. A 
common fault with " home-made" reamers is that they are given 
too much clearance, thus making chattering inevitable. 

HAND-BEAMING. 

In hand-reaming never leave more than 0.003 of stock to be 
removed, no matter what the material may be. On the contrary, 
for machine-reaming, not less than ^ and often -^ should be left; 



2GO TOOL-MAKING 

using reamers with much coarser blades than the usual commer- 
cial ones, and formed so that they can be ground on the points. 
Hand-reamers for use in boiler, bridge work, etc., should be 
of the construction shown in Fig. 284, as they will work better 
than the usual half-round kind. 

rNCKEASLN T G THE SIZE OF A BEAMEK WHE^ 

WOBK 

To increase a reamer to size when worn, burnish the face of 
each tooth with a hardened burnisher, which can be made from a 
three-cornered file nicely polished on the corners. This will in- 
crease the size from two to ten thousandths in diameter. Then 
hone back to the required size. 

To make a tap or reamer cut larger than itself, put a piece 
of waste in one flute, enough to crowd it over, and cut out on one 
side only. In larger sizes (l^-inch or over) put a strip of tin on 
one side and let it follow the tap through. 



CHAPTER XVIII. 

Broaches and Broaching. 
THE OPEKATIOK OF BEOACHIXG. 

THE operation of broaching may be classed under the head 
of punches and dies, as it is analogous with press-work. In 
reality the broach is a punch, the cored or drilled holes in the 
work to be machined by it acting as a die and guide for same. 
The operation of broaching has had great develop- . 

IP! P Hir I 

ment during the last decade, special machines and 
forms of tools having been designed to further the 
use of this interesting and labor-saving process for 
the finishing of work which it was formerly thought 
to be impossible to finish by such means. 

The broach as a tool is usually used for finishing 
holes which have been previously either punched, 
cored, drilled, or bored in metal, the shape of which 
may be round, square, or any irregular shape de- 
sired. Although the broach can be used to advan- 
tage for the finishing of holes by setting it under 
an ordinary power-press, an arbor-press, or a foot- 
or screw -press, the operation can be best accom- 
plished in a press specially designed for the pur- 
pose of broaching. A press of this sort has usu- 
ally an adjustable stroke of from 1^- to 12 inches. 

In Fig. 285 we show a sketch of a broach used 
for finishing a cored hole in a rough casting. The 
tool is 3 x 1 inches, and 9 inches in length. In this tool the 
teeth are very coarse at the lower end, being intended for re- 
moving the bulk of the stock until the centre of the broach is 
reached, when the teeth are sheared in the opposite direction, 
thus breaking the chip off. The teeth in the broach then de- 
crease in size until near the upper end, when they are left the 

261 



Fig. 285. 



262 TOOL-MAKING AND 

one size for about two inches of the remaining length, thus form- 
ing a "sizer" which shaves the hole to a standard size all the 
way through. 

In forcing a broach through a hole it may be best driven by 
a "V" brock, which should be secured in the press-ram in much 
the same manner as a punch would be. Thus when the press- 
ram descends the broach will find its own centre ; while the lia- 
bility of breaking or bending the broach or producing an im- 
perfect hole will be obviated. 

In order to broach holes of considerable length in a press 
with a short stroke, the work may be satisfactorily accomplished 
by using a successive number of blocks. First insert the broach 
in the hole and then drive it down into the same for the full 
length of the press-stroke. Next, insert a block of the same 
thickness as the length of the stroke between the ram-face and 
the broach-end, and then force the broach in a further distance ; 
repeating the operation and using larger blocks until the desired 
length of drive has been obtained. By this method it may be 
well to state that the results attained will not equal the work 
performed on a continuous stroke-press, as the stopping of the 
broach when partly through the work allows the metal to settle 
into the broach teeth, thus increasing the tendency to bend and 
break. 

To-day there are on the market any number of machines 
which have been specially designed for broaching. A number 
of these machines perform the operation by pulling the broach 
through the hole instead of forcing it through. 

AN INTEKESTTNG JOB OF BKOACHING. 

Broaching is very interesting work. For some work the best 
and only way to make a broach is in one piece ; while for other 
work long experience has taught that it is the wrong way. To 
do the job shown in the sketch, Fig. 286, with one broach would 
require a long one, and that would cause trouble; for a broach 
of sufficient length for this work is difficult to turn and mill, 
and to harden and draw, owing to the key way on one side which 
will cause it to spring in hardening ; it would be an advantage if 
it were grooved on opposite sides. 



INTERCHANGEABLE MANUFACTURING. 



263 



The hole in the piece shown in Fig. 286 is broached from - 
to i-inch and a key T ^-inch high formed and is afterward 
drifted to 1-i-inch at the bottom and f -inch at the top ; the thick- 
ness of the piece is f-inch. Over 250,000 pieces have 'been 
made with the broaches as shown, and the loss in broaches and 
pieces was nothing compared with the loss when using the long 
broaches first made. 

The stock for this job was a special tough tool steel. The 
broaches are shown in Figs. 287 to 291 ; they were four inches 
long and of the diameter given. Each was tapered at one end 






FIG. 286. 



FIG. 287. FIG. 288. FIG. 289. FIG. 290. FIG. 291. 



and countersunk at the other, and the top, or male end, was 
milled flat on one side (like No. 4) to fit the punch-press fixture, 
Fig. 292. Xos. 1, 2, and 3 have five teeth per inch, and No. 4 
has six teeth ; it will also be noticed the latter broach is left 
blank at one end ; this- will be explained later. 

The teeth being f-inch from the end, this part was drawn to a 
blue after hardening. This was very important, as the end had 
a tendency to crumble and break out and thus destroy the broach. 
The end was drawn by dipping in hot lead after the broach was 
hardened and drawn to a straw color. For cutting tool steel 
very little clearance was given the teeth ; too much clearance 
would cause the broach to cut ragged. 



264 



TOOL-MAKING AND 



The ^-inch hole to receive the end of the first broach was 
drilled in the stock, and the other end of the broach was inserted 
in the hole H in plate C, Fig. 293. To the plate was secured 
two rods, which had a vertical movement in plate B, light 
springs keeping plate C away from the pnnch. An important 
feature is the hole H, which received the end of the broach and 
prevented its being placed in the wrong position, as each broach 
had to follow exact, owing to the keyway. 

A clearance (shown at D) on each broach served to guide an 
end of the broach while entering. After the first broach was 
entered and forced into the work by the press, the upper end 







* 
t 


C3 

z. 

> 


3 
i- 




2 


E 


a 


ir 














i ! 


1 

1 
1 


j 




1 
I 


/ i 








! 



PUNCH PRESS PLATE,.. 
FIG. 293. 

projected above the work to receive the second broach, which 
was in turn punched through, being followed by broach No. 3, 
and the latter by No. 4. If teeth were cut the full length of the 
last broach, it would stick in the work. To overcome this it was 
cleared at the end, as shown, so that when punched down to the 
end of the stroke the broach would fall through. The work in 
making broaches of this length is simple, as they are easy to 
turn, harden, draw, and grind. 

In punch A a hardened -steel plate, D, was inserted, as at this 
point any wear would cause the broach to twist and spoil the 
key. This is made a driving fit, and can be replaced at any 



INTERCHANGEABLE MANUFACTURING. 



265 



time. The finished hole, Fig. 286, was drifted cold ; and owing 
to the quality of the stock was a neat piece of work. Figs. 293 
and 294 show the drift and the punch-press fixtures. The punch 




A 




FIG. 293. 



FIG. 294. 



for putting in the drift had a steel insert, the same as D in A. 
It is very important in making broaches that the stock be thor- 
oughly annealed, and when broaching use nothing but the very 
best of oil. 



SOME POINTS ABOUT BROACHES AXD BEOACHIKG. 

In order to secure good results in broaching the bottom of 
the tool used should be hollowed out somewhat, so that a nice 
clean chip will be cut from the inside of the hole, and so that the 
tendency to dodge to one side when places in which the cored 
hole is rough or crooked are encountered will be obviated. The 
stripper for the work should be arranged so as to pull off square. 
Otherwise, if the hole is a long one, it will be spoiled when the 
broach is pulled out. 

The special presses provided for broaching are usually back- 
geared and very powerful. It is not well to speed the press too 
fast. In all cases use oil as a lubricant. When the amount of 



266 



TOOI^MAKING AND 



stock to be removed is considerable, it will be necessary to do 
the work in two operations ; too heavy a cut having a tendency 
to make the hole rough. Socket -wrenches or similar fits are 
easily made in this way. If the cuts are made light enough, it 
impossible to broach cast-iron in this way, using for this purpose 
several punches or broaches of different sizes. Such punches 
should be slightly larger at the cutting end, and for the finishing 
cut or last operation if clear through the piece should work 
into a die or the tool will break off or tear away the lower edge 
of the work. The temper should be a trifle harder than that 
given to ordinary punches and dies. A in Fig. 295 shows a side 
view of a broach which was made for cutting out the holes in 
three cast-steel flanges for a steamboat. The holes had been 
cored out of a f -inch bolt instead of a f-inch ; hence the necessity 
for enlarging them. The broach was made with six steps, as 





6 

_^~~- 




X 

^ 




4 






8 


* 1 


K SQUARE STEEL 







L -^ 




- 1 









~~ 




3tt 





FIG. 295. 

shown at A, and with the steps numbered at B. Step 1 acts as 
a pilot and to scrape out the sand ; step 2 cuts on four sides some- 
what, as shown at C, step 3 cuts the hole slightly larger in the 
same manner ; the next three steps cut out the corners, as shown 
in 4, 5, and 6. 

There were ninety holes in all, one-half of which were through 
metal ^-inch thick, and the other through metal f-inch thick. It 
took about three hours to broach them out, driving the broach 
with a sledge, as no press was at hand. The operation of mak- 
ing the tool took about one and one-half hours on the milling- 
machine, using an end-mill. 



INTERCHANGEABLE MANUFACTURING. 267 

BEO ACHING: ITS EELATION TO SHEET-METAL 

WOEK. 

Oberlin Smith, in his "Press Working of Metals," has given 
us the following in regard to the relation of the word "broach- 
ing " to sheet-metal work : 

" . . . The word ' broaching ' has here a very different 
meaning from that given it by the machinist, who applies it to 
the process of forcing a piece of male work through a lower cut- 
ting-die, or pushing a cutting -punch through a hole in female 
work, thereby shaving it to a given size, and really performing 
an operation analogous to planing or slotting. In cases where 
he uses male or female broaching-cutters having a series of teeth 
following each other, and each taking off its own chip, his work 
more nearly resembles milling. In relation to sheet metals the 
word broaching means smashing the work thinner by forcing it 
through a space between the punch and die, as in some kinds of 
tube-drawing, which again is the same as wire-drawing, if we 
imagine the mandrel to be a part of the tube. In the case in 
question a reduction of diameter is being made at the same time 
as the thinning of the metal is taking place. This is much prac- 
tised in cartridge-drawing, especially where it is desirable to 
keep the end or bottom of the work of the original thickness. 
When done, the bottom remains of as much greater thickness 
than the sides as happens to be required and as has been arranged 
for in choosing the thickness of the sheet. In small work of this 
kind the use of a blank -holder, or upper die, is abandoned after 
the first one or two draws, as the .metal is reduced so little in 
diameter in proportion to its thickness that the wrinkles have no 
chance to form. Even if incipient wrinkles do form they are 
quickly crushed out again as the metal is squeezed somewhat 
thinner. In this, as in all drawing, however, the wrinkles must 
never be allowed to get big enough to fold over upon one another. " 



CHAPTER XIX. 

Shop Use of Micrometer-Calipers and the Height- 
Gauge. 

MICBOMETEB-CALIPEBS. 

IN the accurate production of duplicate parts as carried on 
to-day in the economic manufacture of machinery, tools, punches 
and dies, and instruments of precision, accurate gauges are de- 
manded. For years the average machine-shop got along with 
templets and gauges of sheet steel, so-called "limit-gauges," of 
doubtful accuracy and of little value, as they were carelessly 
made and used with indifference. However, we are pleased to 
say, this state of affairs has passed away; and the increased use 
of the micrometer-caliper has enriched the scrap piles of many 
shops with collections of "snap" and "limit" gauges, "temp- 
lets " and " reference " disks ; has increased the economic produc- 
tion of the shops, and made the workmen more skilful. 

To produce accurate work the skilled machinist or tool-maker 
of to-day demands as a first requisite a means of measuring his 
work during the process of machining it to the required size and 
shape; and this requirement is filled when the workman is sup- 
plied with a micrometer caliper and the feed-screws of the ma- 
chine which he operates are fitted with graduated disks. Of course 
it must not be inferred from this that brains are not required 
along with these gauges ; or that an indifferent or careless work- 
man will instantly become a skilled mechanic upon being supplied 
with a micrometer. However, the use of the micrometer will 
improve the poorest workman; as instead of guessing he will 
measure ; he will use his eyes and think ; thus a consequent im- 
provement will take place. 

Among shop managers, superintendents, and foremen, the 
most common. objection raised against the general shop use of 
micrometers is that they are too light, and are liable to get out 



INTERCHANGEABLE MANUFACTURING. 269 

of order when used by all classes of help. Now, while this may 
occur, there is hardly any excuse for it ; any man that is trusted 
with and is capable of turning out accurate work can be safely 
trusted to use a micrometer correctly. To be sure it makes a 
great difference how the tool is handled. It all depends upon the 
workman's sense of touch. The machinist, as a rule, wants in- 
formation as to how much more has to come off after he has 
taken a cut, and so he sometimes forces the gauge in the hope of 
determining by the sense of touch how much remains, to come 
off. This sense of touch differs in mechanics very much. In 
.some it amounts to a considerable exertion of their strength ; 
these are the one who spoil the gauges. 

With the micrometer there is no excuse for the use of strength ; 
it is an adjustable gauge and the machinist knows by reading it 
when the work has been reduced to the size desired. He knows 
also that he may run the screw back at intervals and determine 
the amounts remaining to come off; he may also determine the 
size at the start ; and for sizing a number of pieces he may lock 
it and use it in the same manner as he would a snap -gauge. In 
the use of the micrometer the mechanic has to use his eyes and 
brains more, and his strength becomes an ineffective factor in 
the attainment of the results. 

It is very easy to teach bright apprentices and operators how 
to use micrometers ; in fact, the reading of them to the one-thou- 
sandth of an inch is very simple ; while their reading to one-ten- 
thousandth of an inch can be learned after a little thought and 
practice. The ease with which workmen in general learn to read 
and use these gauges can be inferred from the fact that there are 
any number of small shops in the East at least to my knowl- 
edge, in which accurate work is turned out, where nothing in the 
way of gauges is used but micrometers. As this is successfully 
done on a small scale, I can see no reason why the installation 
of the system on a large scale should present difficulties. 

In all shops in which micrometers are used in place of the 
obsolete gauges, or in shops where they are about to be used, a 
good set of B. & S. test pieces, either end- measures or disks, 
should be provided ; also a man should be detailed to take care 
of the adjustments of all micrometers in the shop; someone who 



270 



TOOL-MAKING AND 



is skilled in such work and who has cultivated a delicate sense of 
touch. In shops where the work done is of great accuracy and 
only the minimum limit of error is allowable, two sets of test 
measures should be provided ; one set to be for general use and 
the other for occasional reference only. The new micrometers 
should be given to the most skilled men for use on the finest 
work only ; while those micrometers that have become worn, or 
are to a certain extent inaccurate, should be used 011 work in 
which a greater limit of error is allowable. Above all, never 
use generally calipers graduated to ten -thousandths, where fine 
measurements are not necessary, as in an instrument of the pre- 
cision of this class a wear is preceptible and important which 
would be of comparatively slight consequence in a caliper that is 
graduated to be read only in thousandths. 

BEADING MICBOMETEB-CALIPEBS TO TEN- 
THOUSANDTHS OF AN INCH. 

While the ordinary reading of micrometers is pretty gener- 
ally understood i.e., reading to thousandths of an inch the 
reading of them to ten -thousandths is not. For the benefit of 
those who do not understand this I explain in the following 
how to do it. 

In Fig. 296 a 1-inch B. & S. micrometer-caliper graduated to 
read to ten-thousandths of an inch is illustrated. The readings 




FIG. 296. 



in ten-thousandths are obtained by means of a veriner or series 
of divisions on the barrel of the caliper on the side shown in the 
cut. These divisions are ten in number, and occupy the same 



INTERCHANGEABLE MANUFACTURING. 271 

space as nine divisions on the thimble. Accordingly, when a 
line on the thimble coincides with the first line of the veriuer, 
the next two lines to the right differ from each other one -tenth of 
the length of a division on the thimble ; the next two lines differ 
by two-tenths, etc. Note the left hand cnt of graduations on the 
barrel and thimble in Fig. 296. 

When the caliper is opened, the thimble is turned to the left, 
and when a division passes a fixed point on the barrel, it shows 
the caliper has been opened one-thousandth of an inch. Hence, 
when the thimble is turned so that a line on the thimble coin- 
cides with the second line (end of first division) of the veriuer, 
the thimble has moved one-tenth of one-thousandth, or one ten- 
thousandth of an inch. When a line on the thimble coincides 
with the third line (end of second division) on the veriuer, the 
caliper has beeu opened two ten-thousandths of an inch, etc. 
Note the right hand cut of graduations, where the line on the 
thimble coincides with the fourth line (end of third division) 
and the reading is three one-thousandths of an inch. 

To read the caliper, note the thousandths as usual, then count 
the number of divisions on the veriner, commencing at the left, 
until a line is reached with which a line on the thimble coincides. 
If the second line, add one ten -thousandth, if the third, two ten- 
thousandths, etc. 

SPECIAL USES OF MICEOMETEE-CALIPEES. 

Besides the uses for which the micrometer was primarily de- 
signed and is generally used, there are any number of special 
uses to which the caliper can be put : In the following I enu- 
merate and describe a number which will no doubt be the means 
of suggesting many others. 

In order to determine whether the dead centre and the live 
centre of a lathe are in line : First, set the centres as near as pos- 
sible by eye ; then carefully centre a piece of stock about six 
inches long; place it on the centre and turn one end for a dis- 
tance of about one-half inch, using a sharp-edged tool so as to 
get a sm ooth surface. Then reverse the stock so that the turned 
end will be at the live centre. Next, turn the other end to ex- 



272 



TOOL-MAKING AND 



actty the same diameter, using the micrometer to gauge it. Now 
clamp the micrometer to the cross-slide of the lathe, so that the 
eud of the barrel or ratchet-stop will rest against the work, as 
shown in Fig. 297. You can now set your centres accurately by 




Shaft 



Deadfieevtre 



Liue&atre 



Micrometer 



ToolPott 




running the barrel out against the nearest end, noting the read- 
ing and running back the barrel, running the carriage up to the 
other end and repeating the operation. A few trials and adjust- 
ments of the tail-centre and both centres will be set dead in line. 
In order to test the lathe to see whether the centres are the 
same height from the ways, the same method can be adopted by 




Cros^Sfidc 



FIG. 398. 

using the micrometer backward, from the top down, or from the 
bottom up, as shown in Fig. 298. 

To line up the centres on a grinder so as to get them dead in 
line the micrometer can be used by fastening the caliper between 
the collars of the spindle where the emery-wheel is usually located, 
in the manner shown in Fig. 299, and by blocking up the spin- 



INTERCHANGEABLE MANUFACTURING. 



273 



die in the most convenient manner. In using the micrometer in 
this manner, however, always remember that all round or circu- 
lar work will have an error twice that evidenced by the gauge. 




FIG. 299. 

That is to say, if the centres show only 0.0012 by the microm- 
eter in the test, they will shown an error of 0.0024 on the 
work. On straight surface work the test will show the actual 
error. 

It will be at once obvious to the practical reader that this sys- 
tem of testing can be applied to almost any machine in the shop. 
On the planer, miller, shaper, or precision -lathe it will be found 
all that can be desired in detecting errors in the platen, vise, or 
fixtures; while when utilized in the lining up of a job with a 
finished surface, it is as good as a surface-tester and lends itself 
much more readily to the work in hand. 
In fact, this system can be almost uni- 
versally applied where accurate work 
from machines is absolutely required. 

The micrometer-caliper can also be 
used as an inside caliper in any hole in 
which it will go in with ease. This is 
shown in Fig. 300, the caliper being 
used to gauge the inside of a large 
cutting-die when grinding it to the finish size. To use the gauge 

in this manner it is only necessary for one to learn to read the 

18 




FIG. 300. 



274 TOOL-MAKING AND 

graduations backwards ; then no difficulty will be experienced in 
using it as an inside micrometer. 

In all shops where micrometers are used generally it will 
faciliate their use and expedite the production of accurate work 
by having the feed-screws of all machines fitted with graduated 
dials ; and if the micrometers in use are graduated to read in 
thousandths, by having the dials to read the same. 

The universal use of micrometer-calipers for regular machine- 
shop gauges is not far distant, as it will not be long before the 
chief and perhaps the only interdiction to their extensive use 
their cost will be overcome. That the demand is growing is 
evidenced by the fact that one concern in the East manufactures 
a line measuring from six to twelve inches for use on the larger 
classes of interchangeable machine work. 

THE HEIGHT-GAUGE AND ITS USE. 

While the micrometer occupies first place among the small 
precision tools of the universal shop, there is another tool which, 
follows it a close second. I refer to the height gauge, Fig. 301 ; 
a tool that although it is used quite generally among tool -makers, 
is comparatively unknow T n outside of them. If more were known 
of the great utility of this handy, accurate, reliable, and almost 
indispensable tool, its use would become common in all shops 
where accurate work is done. By many the height -gauge is 
thought to be merely an accessary to the tool-maker's kit, and of 
no use except in verifying measurements ; when, on the contrary, 
it can be used for a thousand and one jobs in the attainment of 
results with ease which would otherwise be almost impossible of 
attainment w r ere other means used. In accurate work, especially, 
by means of the height-gauge, jobs that appear to present insur- 
mountable difficulties are accomplished with ease. 

In order that the utility and value of this accurate tool may 
become better understood I will present a few examples of its use : 

By far the most usual and common method of striking or 
scribing a line on a piece of work is with the surface-gauge ; set- 
ting the scriber to some graduation on a scale. This method, 
however, is not to be compared with the height-gauge and its 



INTERCHANGEABLE MANUFACTURING. 



275 



scriber in point of economy of time, labor, and worry ; for the 
reason that the height-gauge may be set almost instantly and ac- 
curately when one is familiar with it, and a line may be scribed 
with it at once with the assurance positive that it is in exactly the 
place that one wishes it to be. With the surface-gauge the 
scriber must be raised and lowered many times before the cor- 
rect ( I) height is obtained ; even then the final setting is a guess. 






FIG. 301. 

For example second, let us say that it is necessary to locate 
eight holes in a circular finished casting as per Fig. 303 ; the 
holes to form the corners of two squares, one within the other, 
with the four holes of each equidistant from the centre of the 
casting. The way to accomplish the desired results accurately 
with ease will be to take an angle-plate like 302, true it on three 
of its sides, and then clamp the disk on its face A. The exact 
diameter of the casting in which the holes are to be located is 
found first ; then the height of its lower edge from the surface- 
plate on which the angle-plate rests; then, by means of the 



276 



TOOL-MAKING AND 



veriner on the height-gauge and the scriber which ^omes with it, 
we scribe two lines the required distance apart, equally above 




FIG. 303. 



and below the centre, for the outside square, then two more lines 
for the inside square. Next, without removing the casting from 



Centers 




Centers 



Centers 



Center* 



FIG. 3i)3. 



the angle-plate, we turn the plate on to face B and then scribe 
four lines in a like manner, thus finishing the two squares. All 



INTERCHANGEABLE MANUFACTURING. 



277 



is now ready to drill and tap the eight holes approximately cor- 
rect, where the lines intersect, for the " button " screws, which 
we use to locate the "buttons" true for boring the holes. From 
this example it will be at once obvious that holes may be located 
in a like manner on any given surface, providing that care has 
been previously taken to have the surfaces from which the neces- 
sary measurements are taken perfectly true and square with each 
other. 

For the third example, we will take the block shown in Fig. 
304, which has a hole at C and in which it is desired to drill two 
more holes centrally with the first one way, but at angles with 
it the other, as shown by the dotted lines. We first bolt the 
angle -plate on the table of the miller, square with the spindle, 



ffo/ 



e& 




FIG. 304. 

and then fasten the block to the angle-plate, at the required 
angle with the table. We locate a plug in the hole first drilled 
at C, as shown in Fig. 305, and then find with the height-gauge 
the exact distance the centre of the hole is from the table. Then, 
with a plug in the miller-spindle which must run perfectly true 
we measure from the plug to the table, raise or lower the knee 
until the centre of the spindle is the same distance from the 
table that the centre of the plug in hole C is, setting it horizon- 
tally, by measuring from the plug in the spindle to the angle- 
plate, 'or the edge of the block to be drilled, with the height - 
gauge. We have now everything ready to bore one of the angu- 
lar holes ; which may be accomplished by using a draw-in collet 
end-mill, or a single-pointed boring-tool, to finish the hole. The 
other hole may then be finished in the same manner by reversing 
the block on the angle -plate and proceeding as before. 



278 



TOOL-MAKING 



In conclusion I may state that experience has proved that 
more accurate and expeditious results can be obtained with the 
height-gauge than the surf ace -gauge. Lay out your work with 
the height-gauge ; prickpunch carefully where the lines intersect 



ffnyfe PlaU 




FIG. 305. 

using a glass where unusual accuracy is essential and indicate 
carefully on the lathe face-plate ; drill the hole, and finish it by 
boring. In this manner you will get as near perfect accuracy as 
it is possible to get. 

If you are machinist, tool-maker, or die-maker, learn of the 
multiple uses of the micrometer -caliper and the height-gauge ; 
and your ability to do fine and accurate work will be further de- 
veloped and your earning capacity will be increased. If you are 
a shop manager, superintendent, or foreman, furnish your de- 
partments and tool -rooms with such tools and teach your men 
how to use them ; as by so doing your shop will produce more 
and better work accurately with ease. 



CHAPTER XX. 

Mould Construction. 
MOULDS. 

As not infrequently the making of moulds form part of the 
tool-maker's work it will be well to devote a chapter in this book 
to this interesting branch of his art. 

Moulds are used to-day for the production of a variety of arti- 
cles too numerous to mention. Eubber goods, soft metal ware, 
composition goods, glassware, china, and a thousand and one 
other things that form an integral part of our twentieth century 
civilization, are produced in moulds made by our most skilled 
tool-makers. Let no one think that moulds require but little skill 
to construct ; for if they do they will find themselves greatly mis- 
taken. In order to construct moulds successfully the mechanic 
must be skillful and accurate. In order that the articles pro- 
duced in them shall be as desired, and exact duplicates of each 
other, the moulds must be of the most accurate construction. In 
fact an accurate mould must be constructed in much the same 
manner as an accurate drilling -jig would be, as its products are 
usually of the interchangeable class. 

In order that the tool -maker may be assisted in deciding upon 
the proper type of mould to adopt for the production of an arti- 
cle of a given shape, size, and form from a given material, I 
shall illustrate and describe in the following pages a number of 
sets of moulds of the most approved construction. The descrip- 
tions will also point out the way to construct them properly. 

MOULDS FOE PENCIL CRAYONS. 

Fig. 306 shows a face view of a mould for pencil crayons. 
As will be seen, it was made in two parts and produced twelve 
crayons at once. Two castings A and B, 6 inches wide by 7 

279 



280 



TOOL-MAKING AND 



inches long, with lugs on one end of each for the hinge portions, 
were planed all over, with care to get as smooth and true surface 
as possible. The castings were very close-grained and totally 
free from blow -holes. After they were planed they were scraped 



'v_y vv v_y WV_yV_y v_y v_y 



v_y v_y V^v^/ W v_y.v_y 



FIG. 306. 

on the sides on which the moulds were to be, until they were as 
near true as it was possible to get them. The lugs of the hinges 
were then machined so that A fitted within B snugly. The 
halves were then clamped together and the holes drilled and 
reamed through the lugs for the pins I), which were drhen in. 
The plates A and JS were then held in the vise and milled through 
one side, leaving a rib on the side of each, as shown at C C, and 
a depression R between them. While they were still clamped 
together the centres for the twelve moulds were laid out and 
prickpunched. 

Next the pins D D were removed and the plates separated. 
We now have a centre mark on the face of each plate for each 
of the twelve moulds. The plate A was then strapped on the 
table of the miller, dead square, and a line was struck from each 



FIG. 307. The Reamer. 

centre across the plate. A convex cutter, of T 1 ^-inch radius, was 
then used, and, starting at the mark, was run along the line on 
the face to within J-inch of what was to be the total depth of the 
mould. This was done on all of the twelve centres, and the 
other plate was milled likewise, so that when the pins D D were 



INTERCHANGEABLE MANUFACTURING. 281 

inserted and the plates closed and clamped together there were 
twelve holes, ^-inch in diameter, straight through the centre of 
them, or a half of a ^-inch circle in each plate. 

The plates were then stood with the side c c up, and a 
drill J T of an inch under the final size, and extra long, was run 
down through each of the ^-inch holes to within f -inch of the 
bottom, the ^-inch hole in each keeping the drill perfectly cen- 
tral. A special reamer, of the shape shown in Fig. 307, was then 
made and fed down into the hole left by the drill, and by feeding 
down very slowly a smooth round hole was made with the shape 
of the point in the bottom. All the twelve holes were gone over 
several times, until the exact depth was reached in each. The 
mould was then opened, and all the dirt and chips were cleaned 
out. It was then closed and reclamped. Several pieces of 
Y^-iuch drill-rod which had been roughed all over were inserted 
one in each of several holes and melted lead poured around 
them. When they were cold the mould was opened and the lead 
forms were withdrawn, thereby furnishing several good laps. 
The laps were run at a high speed in the drill-press, using a gen- 
erous amount of oil and emery, and the holes, or moulds, were 
lapped and polished to a nice, smooth finish. The plates were 
then opened, and after being well cleaned with benzine there 
were seen twelve perfect semicircular grooves of the size re- 
quired in each plate, with dead-sharp edges that would leave no 
fins on the work. The pins D D were then eased a little, so that 
ttie mould could be opened without difficulty. 

The next thing to be done was to make the latch F, shown in 
Fig. 308. This was made of i-inch flat steel and fastened to 

J 



OOOCpOOOOOQQ 




FIG. 308. 



the plate A by a shoulder-screw. A small stud was let into F, 
for a handle H. The spring Q, of stiff spring steel, was made 
and fastened so as to keep a strong tension on the latch F. The 
lock-pin Ewas then made and hardened and inserted in the 



282 TOOL-MAKING AND 

plate B so that, in order to hold the two halves of the mould 
fast and snug, the half B was brought down sharply ou to A, 
and the pin E striking the latch F it was forced back until it 
snapped over the pin, thereby locking it. This proved a simple 
and reliable latch and was quick to manipulate. The swinging 
plate J for closing the channel E was then made of flat, cold- 
rolled steel and worked out and finished to the shape shown, 
with a small handle at K and swinging on the screw L. The 
stop-pin M was let into A and filed off so that the plate would 
swing over and rest on it, thereby closing the channel and pre- 
venting the liquid material from running out. The other end 





FIG. 310. FIG. 311. Butt Mill. 

was closed likewise, and the mould was then complete. It pro- 
duced nice, smooth crayons without the trace of a fin or a lump 
on the entire surface. A slight shrinkage which resulted in 
them after they became hard, allowed of their easy removal from 
the moulds. 

MOULDS FOR LEAD BALLS. 

In Figs. 312, ,313, and 314 is shown a mould for casting a lead 
ball on to a sheet-brass frame, as shown at Fig. 309. This device 
was used as part of a balancing mechanism, and it was necessary 
to have the balls all exactly the same weight and size, and in the 
same position on the frame. The mould used is shown in three 
views. Fig. 312 shows an inside view of each of the two sides ; Fig. 
313 shows the bottom, and Fig. 314 the top. The two halves of the 
mould were castings, and were machined all over to the same 
size, with one dead-smooth side. After being scraped in order 
to true them, one of them was held in the milling-vise, taking 
care to have the vise true and the work down solid. Then the 
butt-mill shown in Fig. 311 was held in the small chuck and the 
table moved until the mill, while running, just touched the end 
of the casting at C; the table was then moved outward and along 



INTERCHANGEABLE MANUFACTURING. 



283 



a certain number of thousandths of an inch (and a memorandum 
made of it) for the first hole of the mould. Care had been taken 
to finish the butt-mill to a perfect half-circle of the radius re- 




r V 



FIG. 312. 



quired. The work was then fed against it and the mill let in the 
required number of thousandths, or to the depth of exactly half 
the diameter of the mill. The screw-dial graduation was then 



FIG. 313. 



noted, and the work brought back and moved along for the next 
hole, and so on until the twenty-one halves were finished. 

The other side D was then held in the same manner, the mill 
set and fed in the same number of thousandths as before and 



G 


G 


fT m 


T T 


:;: : c 


c| Tf, 




^""""-^VTr! ' 


|j^_._e. 06 o ooo 




: D 


D g>: 



FIG. 314. 

then each one milled to the same depth as the others. After this 
was done the halves were removed, and two brass balls were 
turned up and finished to exactly the same diameter as the 
moulds, and one inserted in the last hole in each end of the plate 
C. The other plate D was then placed on the top, thereby locat- 
ing the half-moulds perfectly true with each other. A hole was 
then drilled at each end and. reamed for the dowel-pins FF which 
were made and driven into C. The holes in D were eased so 



284 TOOL-MAKING AND 

that D would go on the pins nicely. This proved a simple way 
of locating the molds exactly true with each other. The holes 
for the cap -screws G G were then drilled and the two sides C D 
held fast together. A cutter just the thickness of the stock used 
for the frames was then run straight through at L where the 
two pieces C D lay together, to the depth shown. C and D were 
then separated, and the centres laid out for the holes opposite 
each mould, as shown at 1 1. The holes were then drilled about 
^ inch deep, and reamed to allow the pins to be driven in to hold 
the frames in place, as shown in the upper right-hand mould. 
Each of the sides was then set up in the shaper and a tool just 
the width of the frame at B centred with the holes 1 1 opposite 
each mould, and a channel planed into the centre of each mould, 
as shown at J, to the same depth as L. The idea and form are 
shown clearly in Fig. 312. The parts C and C were then put to- 
gether and the screw G tightened and the holes drilled through 
which the lead was to run into the moulds, as shown at H, using 
a No. 40 drill and running into the centre of each mould, leav- 
ing half a hole in each. The sides C and D still together were 
then held in the miller-vise, and an angular cutter was used to 
mill a trough for the metal at K to the length and width shown, 
and, for depth, to within -^-inch of the moulds, leaving the 
small channels as shown. The two sides were then separated and 
the faces polished with fine emery-cloth and all the burrs re- 
moved, being careful to leave the edges of the moulds sharp. 
The small pins were made and driven in to the holes 1 and then 
filed down to just the thickness of the frames, and the tops 
slightly rounded. A frame was then entered on to each of the 
pins, as shown at M, thereby holding them all central, the chan- 
nels J keeping them steady. The two sides were then put to- 
gether, and the mould being complete, it was held in the vise. 
The lead was heated to run freely, poured into the trough K and 
running through the small holes H into the mould. After the 
metal had set, the screws were loosened, D lifted off, the cast- 
ing removed, and the balls chipped off at the small neck caused 
by the holes H, leaving twenty- one balancing frames with a per- 
fect half at the end of each, all exactly the same. The one thing 
necessary in making a mould of this kind is a perfect mill and 



INTERCHANGEABLE MANUFACTURING. 



285 



accurate spacing, and the work resulting will show no fin. The 
machine used was a Cincinnati universal, and it was surprising 
how dead accurate the spacing was, there not being a difference 
in any of the work produced, either in size or shape. 

MAKING MOULDS FOE TELEPHONE-RECEIVER 
PIECES. 

The moulds here shown in Figs. 315, 316, and 317 are of a 
type used in manufacturing imitation rubber or composition 
goods for various purposes, such as syringes, bicycle handles and 




FIG. 318.-The Piece 
to be Made. 






FIG. 319. 



parts of the telephone. The moulds were used for moulding the 
receiver case from a composition which, when hard, closely re- 
sembles rubber, and is known as electrose. Moulds of this con- 
struction are used in the hydraulic press, and the composition is 



286 



TOOL-MAKING AND 



in a liquid form when pressed into the mould. The article pro- 
duced is shown in a cross-section in Fig. 318. The top or face 
is concave and the edges are rounded. The case is thin at the 
centre and heavier at the outside, terminating in a square shoul- 
der and a thread of 18 -pitch. There is a flinch hole through 
the centre. 

For the mould, pieces of flat soft steel were plaued, clamped 
with the smooth sides together, and a hole E at each end drilled 
and reamed for dowel-pins. The pins were forced tightly into 
the lower plate and projecting properly into the upper plate. 



n 



ra. 






FIG. 320. 



FIG. 321. 



FIG. 323. 



The sides and ends of the plates were then squared together in 
the miller, and the twelve holes A were drilled through both sec- 
tions and reamed to finish size. A pair of templets of the inside 
and outside shape of the article were filed out and then special 
couuterbores, finishing-tools, and the tap were made. The first 
tool, Fig. 319, was for the too of the case in the upper section, 
and, Fig. 320, was for the face of the core F in the lower section. 
N is the forming- and c fitting-edge and the hole fits the stem of 
the core. The straight face couuterbore Q, Fig. 321, finishes the 
twelve moulds in the lower plates, leaving them square at the 
bottom and sizing them for the tap. This tap, Fig. 322, as well 
as the three counterbores, had a central or guide -pin fitting for 
the reamed holes. 

The upper plate was clamped (not too tightly) to the drill- 
press table, with one of the holes A directly under the stem en- 
tered the hole T t as shown in the cross-section of the plate. The 



INTERCHANGEABLE MANUFACTURING. 287 

coiinterbore was then fed down into the plate to the proper depth, 
and all the twelve holes were finished in this manner, which com- 
pleted the upper plate, except the lapping. 

The first comiterboriug of the lower plate was accomplished 
in the same manner by the flat-faced couiiterbore, Fig. 321. The 
next operation was to tap the holes, which was done in the same 
drill-press, running very slowly and using plenty of soap -water 
as a help in cutting, and by careful work, and by running the 
tap in and out a few times, a sharp, smooth thread was secured. 
The numerous flutings of the tap, Fig. 322, worked admirably. 
There was also very little lead to the tap, as we wished the first 
thread in the finished case to be as full as possible. 

The cores were then made of machine steel, first cut into 
lengths for two. These pieces were first turned at both ends to 
form the stems Z> to be driven tightly into the hole A. The pieces 
were then cut in two and held by the stem in a nose -chuck that 
ran perfectly true, when the stud at the opposite end was fin- 
ished to fit nicely in the holes A in the upper plate. After this 
was done to all of them, the facing- or forming-mill, Fig. 320, was 
used for the face of the cores. The cores being held by the stem 
D in the nose-chuck, the centre in the end of the shank of the 
facing-mill was placed on the tail -centre and the short stem, 
turned on the face of the core, entered the hole in the facing- 
mill, which was then fed in until the shape and size desired was 
produced 011 the face of the core. The twelve cores were then 
highly polished and driven tightly into the hole A in the lower 
plate. All burrs thrown upon the face of the plate by the tools 
used were then removed, leaving a sharp edge to each of the 
moulds. 

There then remained to finish the moulds the lapping and 
polishing of the upper plate which formed the faces or tops, and 
which required a high shining polish as they left the mould. 
We made a few lead laps by pouring lead into the sections B, 
casting them around steel stems, which in use projected into the 
holes A, and then, by using flour, emery, and oil and running the 
laps as fast as possible, the moulds were lapped to a finish and 
polish that was very nearly perfect. By putting the two plates 
together it was seen that there was not the slightest defect in the 



288 TOOL-MAKING AND 

alignment of the holes A in both, testing them as we did with a 
standard plug-gauge. One side of each of the plates was then 
marked " Front" to avoid mistakes. 

When moulding the cases, the upper plate was removed, and 
the composition was poured over the face of the lower plate. 
The upper plate was then replaced, and the projecting stems of 
the cores F in the lower plate entered the holes A in the upper 
plate, thereby preventing the liquid from squeezing out and also 
forming the hole J in the finished case. The two plates were 
then placed under the hydraulic press and sufficient pressure was 
brought down on them to press the fluid into every portion of 
the moulds, the pressure being so great as to force every bit of 
surplus composition from between the sections. This composi- 
tion was used while very hot, and required a few seconds to cool 
before removing. When cooled, the upper section was removed, 
and the slight shrinkage resulting from the cooling allowed the 
finished cases to be removed by screwing them out of the lower 
plate by hand. When thus removed they had a fine, smooth 
polish on all the outer surfaces and a good, sharp, smooth thread. 

HOW AN ACCUEATE SET OF MOULDS WAS 
MACHINED IN THE PLANER. 

In Fig. 323 are two views of the finished lower section of a 
mould used for moulding square sticks of crayons with one end 
curved and tapered, as shown in Fig. 324. There were ten sets 
of these moulds to be made, and as we were getting a good price 
for them we were glad to get the job. Now, as will at once be 
seen, the job is a milling job, and the universal milling-machine 
the machine to do it in. As we had no milling-machine, how- 
ever (universal or otherwise), we had to look around for other 
means. 

At last we decided that they could be finished throughout in 
the planer by the use of a few special tools and attachments. 
Fig. 325 shows how the sections of the moulds are cored out at 
the back at A A, leaving a rim all round the outside. These 
sections, or plates, were of cast-iron of very close grain. The 
twenty castings for the ten moulds were first planed on the top 



INTERCHANGEABLE MANUFACTURING. 289 

and bottom, and the mould face of each scraped, so that the sec- 
tions would surface at all points. The sections were then paired 
and the holes B B drilled and reamed through them, in the 
positions shown, for the three dowel-pins of Stub steel. These 



THE JOB AS FINISHED IN THE PLANER. 





i\c 



PLAN VIEW OF LOWER SECTION OF MOULD. 






CROSS SECTIONAL FRONT VIEW. 



FIG. 323. 



pins were driven tightly into one section of each of the ten 
moulds, and the holes in the other sections eased up. The two 
sections of each mould were then numbered and the moulds, with 



FIG. 324. The Piece Produced in the Moulds. 



the sections clamped together, were then strapped on the planer- 
bed and their four sides planed square with each other and with 
the mould faces of the section, care being taken to finish the lot 



FIG. 325. 

of ten to the same width and length. We were now ready to 
finish the moulds proper, and to do this the tools and fixtures 
shown in the accompanying illustrations were made. 

As seen in Fig. 324, the crayons produced in the mould were 
required to be T %-inch square, with one end tapered and curved 
19 



290 



TOOL-MAKING AND 



to a l^-inch radius. They were to be finished so that they would 
present a smooth surface 011 all sides, without fins and with the 
ends tapering symmetrically. To accomplish this result in the 
planer it was necessary to provide means for raising the forni- 




FIG. 326. 

ing-tool (for finishing the moulds) so as to produce the shape 
desired. The first thing made was a templet. This templet was 
worked out with one square side to work from and then finished 
to a l^-inch radius. It was used to finish the cam shown in two 
views in Fig. 326 and on the 
planer-bed in Fig. 327. This 
cam was of cast-iron with ears 
at each end to admit fastening- 
bolts, and with the cam faces 
long enough to take in the entire 
length of mould sections. It was 
first planed on the back and the 



CAM FOR RAISING TOOL-HOLDER. 





FORMING TOOL. 



METHOD OF FINISHING THE MOULDS AND DUPLICATING THE CURVER TAPER ENDS. 



PLANER BED. 



FIG. 327. 

tongue G fitted to the central slot in the planer-bed. The cam 
face F F was then planed up and finished to the templet, shown 
at left of Fig. 326, after making sure that it was at right angles 
with the sides of the tongue G. The front side of the casting was 
also squared so as to have a locating side for the mould sections to 




INTERCHANGEABLE MANTJF ACT VEIN. 



291 



square against. Next canie the tool -holder. This was got out of 
a bar of 1^-inch square mild steel, bending and drawing down one 
end to If by , to the shape shown in the front and side views 
of Figs. 327-330. The end of the extension at N JV r was milled 
through with a f -inch cutter to admit the roller of machine 
steel, which was finished to fit the slot N IV snugly, and to If -inch 
in diameter, located by the T 7 g--inchstudPtoTevolve freely within 
the holder. A f -inch square hole was worked through the holder 
to admit the forming-tool, Fig. 331, care being taken to get it 
square with the sides of the roller 0. A hole was also drilled and 
tapped to admit the set-screw Q for holding the forming-tool. 
This tool, Fig. 331, was of f -inch square tool steel, finished at E 
to a y^-inch right angle, terminating in a square surface on each 
side at S. The correct shape of the cutting portion was carried 
back to the full thickness of the tool, giving the cutting-edge the 
amount of clearance shown. This completed the tools necessary 
to finish the moulds in themselves. 

Now, as will be seen in Fig. 323, the moulds are constructed 
to produce twelve crayons, and it is necessary to space the twelve 
moulds C accurately, so that those in both sections will coincide 



INDEX NOTCH. 





FIG. 328. 



with each other perfectly when the sections are fastened together. 
To do this, some -kind of an indexing device was necessary. The 
use of the notched hand-wheel, Fig. 328, and the "flopper" or 
index-pawl, Fig. 329, answered for this, and allowed of the spac- 
ing of the moulds being accomplished with rapidity and very lit- 
tle trouble. This hand-wheel was fitted to key on to the horizon- 
tal feed -screw of the planer and had a notch cut into its rim in 
the position shown. The " flopper "or index-pawl consists of 



292 



TOOL-MAKING AND 




FIG. 330. 



fORMING TOOL. 



three parts : the back-plate /, the flopper or pawl J, finished at 
K to fit the notch in the hand-wheel, and the shoulder-screw L, 
for fastening the parts together. This completed all fixtures 
necessary to the finishing of the moulds. 

The manner of finishing the sections in exact duplication of 
each other and spacing them correctly is shown in Fig. 327. 
This is sufficiently clear to be understood with a 
short description. The cam for raising the tool- 
holder is fastened to the planer by bolts at either 
end. The section of the mould marked "the work" 
is located squarely against the square front of the 
cam; lengthwise and sidewise against the stop. 
It is then clamped securely to the platen of the bed. 
The tool -holder is now fastened in the tool -post the 
apron of which has first been set perfectly square 
with the planer-bed. The forming^tool is fastened 
within the holder squaring it with the work by 
means of the parallel edges S S and allowing it to 
project out of the holder so the point of the cutting- 
edge is yTg-inch below the face of the roller, as in 
Fig. 327. The stroke of the planer-bed is then set, 
the hand- wheel fastened on the feed-screw, and the 
" flopper" clamped so that the end K will enter the 
notch in the hand-wheel, the back-plate of the " flopper" being 
clamped to the upright side of the planer. 

Everything is now ready: Starting from one side of the 
mould-plate, the forming-tool is moved over by revolving the 
hand- wheel a given number of times, and the indexing-pawl is 
dropped into the notch. The planer is then started and the form- 
ing-tool is gradually raised, thereby finishing and cutting the 
mould at this end in exact duplication of the shape of the cam 
face. To gauge the depth of the moulds the tool is fed down un- 
til the straight edge S S of the tool touches the face of the mould- 
plates. When the first mould is finished the tool is moved over 
the necessary distance by revolving the hand -wheel and indexing 
in the notch, and the operations are repeated until all twelve of 
the moulds in the section -plate are finished. The plate is then 
removed and another set up in the same manner and finished. 



R 

FIG. 331. 



CNTEECHANGEABLE MANUFACTURING. 



293 



The twenty sections or mould- plates are all finished in this man- 
ner, each one being an exact duplicate of the other, and all coin- 
ciding perfectly when put together. 

The method used here for finishing these moulds can be 
adapted for a large variety of different work, as will be at once 
seen, and the labor and expense incurred will not exceed that 
called into play if the work was done in the milling-machine. 

MOULDS FOB BICYCLE HANDLE-TIPS. 

In Figs. 332 and 333 are shown plan views of the top and 
bottom, respectively, of a set of moulds for the moulding of com- 
position bicycle handle-tips, and in Fig. 336 a cross-section of 
the mould complete. The piece produced is shown in Fig. 335 
and the drawn and perforated tin shell which forms the skele- 
ton of the work, and around which the composition material is 



FIG. 333. 

moulded, is shown in Fig. 334. The perforations in the shell or 
ferrule are to allow of the composition running into them when 
the tips are being moulded. The moulds shown produce four- 
teen tips at a time, and as the construction of them entails con- 
siderable practical knowledge and skill, it is of sufficient interest 
to describe. 

Two mild-steel plates for the two sections A and B of the 
moulds which form the. top and bottom respectively, were first 
planed all over, and one side of each scraped until they surfaced 



294 



TOOL-MAKING AND 



when placed together at all points. Both plates were then 
clamped together and holes drilled and reamed through both for 
the three taper dowel-pins C C C. The pins were then got out 




FIG. 333. 

and driven into the bottom plate, and the two sections placed to- 
gether, and a cut taken off all four sides to get both plates dupli- 
cates of each other. The top section was then removed from the 
other and the face laid out for the fourteen cores C in the rela- 
tive positions shown in the plan views, Holes were then drilled 
through the plate at these points and reamed to size ( T \-inch), 





FIG. a34. 



FIG. 335. 



FIG. 336. 



and then countersunk slightly at the back. The two sections 
were then reclamped together, the three dowels C C C locating 
them and the holes in the top section transferred to the lower, 
drilling into a depth slightly less than the total depth to which 
the moulds were to be finished, as shown at E in the cross-sec- 
tional views, Fig. 336. The upper section was now removed and 
the holes drilled in the lower section counterbored to ^-iuch in 
depth, and in diameter to the size of the reamer, Fig. 337. The 
semicircular channels in the face of each mould at F were then 



INTERCHANGEABLE MANUFACTURING. 



295 



let in, and finished by using the tool shown in Fig. 338, the end 
of which, at H, fitted the holes reamed by the reamer, Fig. 337, 
snugly, the cutter J finishing the channels to the required 
depth. A finishing, reamer of the exact taper and size required 
was then let in, finishing the moulds to the shape and depth 
shown in Fig. 336, the upper edges or largest diameter of each 
just meeting the inner edges of the semicircular channel F, leav- 
ing a sharp edge all around. The moulds were then lapped to 
a high finish, getting all marks and scratches out by the use of 



FIG. 337. 




FIG. 338. 



FIG. 339. 



the copper expansion lap shown in Fig. 339, and flour, emery, 
and oil. The lower section of the moulds was now complete. 
To finish the upper section there remained the fourteen cores, as 
shown in the plan view, Fig. 332, and in the cross-sectional views, 
Fig. 336, at G. These cores were made in the lathe, and were of 
machine steel, first cutting off pieces of sufficient length to get 
out two cores, and then centring them and turning down each 
end to fit tightly the reamed holes in the upper-section plate. 
The pieces were then cut in two and held in a nose-chuck by the 
finished stems, and the core faces turned and finished to the re- 
quired shape and size with a forming-tool that is, to just fit the 
inside of the tin ferrules, Fig. 335. The stems of these cores 
were then driven into the holes in the upper sections, shoulder- 
ing tightly within the plate as shown at D. The mould was now 
complete and ready for w^ork. 

One of the perforated tin ferrules, Fig. 335, was slipped on 
to each of the cores and the composition to be moulded spread 
into the moulds E. The two sections were then located together 
by the three dowels C C C, and the mould placed under the 



296 TOOL-MAKING AND 

hydraulic press and the two sections forced together, which 
caused the composition to compress to the limit, with the surplus 
forced out from each mould and into the semicircular channels 
in the face of the sharp edges on the insides, trimming the stuff 
from that within the moulds. The mould was now removed from 
the press and the sections separated, when, by rapping the lower 
section and the back with a mallet, the moulded pieces dropped 
out, the result being fourteen highly finished tips of the shape 
shown in Fig. 344. The perforated tin ferrules on the inside of 
the tips made them strong and durable, and the presence of the 
pierced holes L around the shells for the composition to run 
into, eliminated the possibility of the two parts separating, or 
the composition loosening or chipping off. 

MOULDS FOE " POKEK-CHIPS. 

In Fig. 340 is shown a cross-section view of a mould for 
poker-chips, and in Fig. 341 a plan view of the bottom section. 
As both sections of this mould are exact duplicates of each 
other, the one illustration will serve for both. The manner of 




FIG. 340. 

preparing the mild -steel plates for the sections M and N, Fig. 
340, and the manner of locating them by the three dowel-pins 
000 are the same as that pursued in the other. As can be seen 
in the plan view of the section-plate, Fig. 341, the mould had a 
capacity of sixteen chips. The manner of spacing these moulds 
and finishing to coincide with each other is as follows : The two 
plates after being doweled together are planed square on all 
sides ; one side of each then marked to work from, choosing op- 
posite sides. One of the sections is then clamped facing the 
spindle to an angle-plate on the universal milling-machine, with 
the marked end resting squarely on the miller-table. The form- 
ing-mill, Fig. 342, is then held in the miller- chuck, and the table 



INTERCHANGEABLE MANUFACTURING 



297 



raised until the work is in line with the first row of moulds. 
The table is then moved along until the cutter will just touch the 




FIG. 341. 

side of the plate. We now move the table longitudinally the 
exact distance required by noting the graduated dial on the 
feed-screw and the first mould is finished by moving 
the work against the cutter ; letting it in the number 
of thousands required. The work is then backed out 
and the table moved for the next mould, treating 
each mould of the first line in the same manner and 
getting them exactly the same number of thousands 
apart. When the first row is finished, the table is 
raised the same distance as the space between the 
first row of holes, then, by starting from the same side 
for the first row, the second row of holes is finished, 
and so on until all are complete. The one thing nec- 
essary is the accurate spacing and sinking of the 
moulds, being sure to take up all back lash in the feed- 
screws before starting the divisions. When letting in the forming- 
cutter, a generous supply of oil was kept running on the cutter, 




FIG. 342. 



298 



TOOL-MAKING AND 



the cutting-edges of which had been ground and oil-stoned to 
take smooth polishing cuts. 

The finishing of the other sections was accomplished in the 
same manner as the first, starting from the marked side and 
working from it as in the other. In the plan view, Fig. 341, Q Q 
are the moulds and It E the semicircular channels for the surplus 
stock to run into. These moulds were required to be finished so 
that the outer edges of the " chips " produced would be about 
0.005 higher than the centres, this being necessary in order for 
the chips to "stack "well and even. The moulds were lapped 
and polished smooth by means of a lead-lap in the drill-press, 
running it at a high speed in order to get a high finish in the 
moulds. 

SPHEKICAL MOULDS. 

Moulds and dies for spherical forms of various radii, such as 
globes and rings, often have to be formed in the lathe. Such 
moulds are used particularly in rubber factories for balls and 




FIG. 343. 

bicycle tires, and the little tool illustrated in .Figs. 343 and 344 
was designed for such requirements, as it was found rather ex- 
pensive to make forming-tools for each size of mould that had to 
be made. The fixture was designed to be bolted on to the car- 
riage of the lathe by bolts in the T-slot of the tool-carrying block, 



INTERCHANGEABLE MANUFACTTJEING. 299 

thus giving it all the ordinary movements given to a lathe-tool, 
with the additional circular ones. 

The tool, as shown in the drawing, consists of the cast-iron 
base, having a tongue which fits the T-slot of the tool-block, and 
is firmly held thereon by the bolts shown. A cap is fastened to 
the base by counter bored screws, while projections upon it and 
a groove in the base serve to locate the cap. The worm-gear, 




FIG. 344. 

having trunnions integral with it, is journaled in the extension 
or wings of the base and cap. Meshing with the worm-gear is 
the worm, the shaft of which is journaled by the base and cap 
and extends toward the front of the lathe, where it terminates in 
the hand-wheel at a convenient length. An oblong slot is cut 
in the worm-gear to receive the turning-tool, which is fastened 
by the central set-screw. 

As moulds and dies are usually made in halves, it is not often 
required to turn out more than this, but proper proportioning of 
the fixture allows as much as two -thirds of the sphere to be 
turned out. The device, of course, will turn out moulds for cir- 
cular rings as well as for balls by simply setting it out from the 
line of centres to the required radius. 



CHAPTER XXI. 

Special Tools, Fixtures, Devices, Arrangements, Con- 
trivances, and Novel Methods for Metal- Working. 

THE DEVISING AND CONSTEUCTING OF SPECIAL 

TOOLS. 

WHILE the constructing of the regular types and standard 
classes of tools necessitates skill, accuracy, judgment, and experi- 
ence on the part of the tool-maker, it is in the devising of special 
means for the rapid and economical production of special work 
that his ingenuity is utilized. The ability to devise special tools 
for special work is one to be prized, and should always be en- 
couraged and developed. In this chapter are illustrations and 
descriptions of a large variety of special tools, fixtures, devices, 
arrangements, and novel methods for metal -working ; by making 
himself familiar with them the mechanic will find no difficulty in 
devising means for the rapid production of any special part; 
while the descriptions of the proper ways to make them will 
show how to avoid all unnecessary expense and labor. 

A SET OF TOOLS FOE MACHINING A CAM. 

The illustrations show a set of tools for machining a repeti- 
tion casting of unusual shape, which was used as a cam on an 
automatic machine for making fruit -baskets, and, as some of the 
tools are of a novel and improved design, a slight description of 
them will suggest their use for other work. 

The casting machined is shown in Fig. 345. It is, to say the 
least, a rather difficult piece to machine, because of the irregular 
cam surface. This cam surface was required to be finished very 
accurately and so that the castings, when finished, would inter- 
change perfectly. The other portions of the casting to be ma- 
chined so as to interchange were the boring and reaming of the 

300 



INTERCHANGEABLE MANUFACTURING. 



301 



hole A, the facing of the hub at G, of the sides (7, and the finish- 
ing of the conical surface at D. The hub B was left rough. 

The number of operations required to finish the casting was 
three the first being done in the turret-lathe and the other two 




FIG. 345. 



in the engine-lathe. The first operation consisted of boring the 
hole A and reaming it, facing the hub G, and machining and fin- 
ishing the conical surface D.. The tools used in this operation 




FIG. 346. 



are shown in Figs. 346 to 350. Fig. 346 is a combination boring 
and hub-facing tool used to bore the hole A and face the hub G 
at the same time. It consists of a long stem H y with the cutter 




/in a slot in the end held by the taper-pin J, and the hub-facing 
tool-holder K, which is located on the bar by the set-screw L, 
the point of which screws into a milled channel in the cutter- 
bar, as shown at Q. The hub-facing cutter N~ is held in position 



302 



TOOL-MAKING AND 



by the two set-screws N N. P is the usual split bushing as used 
in the turret-lathe. 

For reaming the hole A the reamer Fig. 357 is used. This 
reamer consists of the body Q, of tool steel, and six cutters or 
blades T. These blades are let into inclined channels, as shown 
by the dotted lines at U U, to allow the readjustment after being 
worn, or after grinding. The blades are held by taper-headed 
screws W which are let into the centres of the narrow-sawed slots 
V. By tightening these screws the metal is forced tightly against 
the blades, thus holding them securely. 

Fig. 348 shows the tool used for roughing off the conical sur- 
face S. The tool has three cutting-points K and is gradually 




FIG. 348. 

slid along under the surface by the hand-lever, the shank of the 
tool being held in the tool -post. This surface was finished by a 
flat-bladed tool of sufficient width to take the entire line at once. 
The second operation, facing the two sides C C, thus sizing 
the width of the cam face, is done in the lathe by the special 
double-facing tool, Fig. 349. Three castings are located on an 



INTERCHANGEABLE MANUFACTURING. 303 

arbor at once and fastened by a nut. The tool is held in the 
tool-post in the usual way. 

The last operation, machining the cam surface, was the most 
difficult. It also was done in the lathe with four special fixtures. 
These were: A special slide-rest for the cutting-tool, a special 







FIG. 349. 



cross- slide for the lathe, a combined master- cam and chuck, and 
a locating- and supporting-stud for the work. These fixtures, in 
position on the lathe with the work, are shown in Figs. 350 and 




FIG. 350. 

351. The master-cam and chuck was a forging, which was first 
fitted to the spindle of the lathe, after which the chuck portion 
was finished with an internal conical surface at / 1 as a locating- 
point for the conical surface D D of the work. The cam portion 
was then laid out and finished on the universal milling-machine. 



304 



TOOL-MAKING AND 



The stud or arbor for the work was of tool steel finished as 
shown, hardened and screwed tightly into the chuck portion of 
the master-cam, shouldering on it at // H as shown ; the surface 
M was then ground to fit the work. 

The special cross-slide for the lathe is in reality a compound 
rest, the only difference being that the smaller rest does not swivel. 
The cam-roller was of tool steel and was hardened and ground 
to a smooth finish and located on a hardened and ground pin G 




FIG. 351. 

within the bracket K. A chain R is attached to the hook at the 
back of the slide and is supported by a roller at the back of the 
lathe, with a heavy weight fastened to the hanging end of it. 
Thus the movement of the cross-slide is derived from the master- 
cam S 8 working against the cam-roller. As can be seen, the 
construction of the cross-slide is strong and the rigidity of the 
cutting-tool is insured. The cam surface was first turned to 
within a few thousandths of an inch of the finish size and then 
finished to gauge by grinding this being easily accomplished by 
the use of a small tool-post grinder driven by a round belt from 
a drum overhead. 

CUTTING A COAESE-PITCH SCREW. 

Fig. 352 is a sketch of a coarse-pitch screw which, because of 
the unusual pitch, was cut and finished under difficulties. The 
screw was 30 inches long, 2 inches in diameter, with one thread 
to 3 inches. After rigging up the gears on the strongest lathe in 
the place it was found that the slowest speed we could get was 
too fast, and after breaking all the teeth a new pair of gears was 



INTERCHANGEABLE MANUFACTURING. 305 

got out to replace the broken ones. A piece of machine steel 
was turned up and reduced at one end to screw into the tapped 
hole for the gear-screw in the end of the lead-screw of the lathe, 
and an 8-inch pulley keyed on this extension piece. A spare 
countershaft was now located and fastened to the floor. The 
driving-belt was removed from the lathe and we then belted 



FIG. 352. 

from the main shaft to the countershaft on the floor and from 
the countershaft to the pulley of the lead-screw. We thus re- 
versed matters, and instead of the lathe-spindle driving the lead- 
screw, we had the lead-screw drive the spindle. Thus while the 
lead-screw fed the thread-tool at the proper speed the work 
turned very slowly and the screw shown and several others, as 
well, were finished without any further trouble. 

MAKING THIN THEEADED BEASS EINGS. 

In Figs. 353 and 354 respectively are shown the means used 
for accomplishing a nasty little job in a very simple manner. 
We were making a lot of thirty-two acetylene-gas lamps, and 
during the process of manufacture it was necessary to make and 
sweat a threaded brass ring into one of the shells. These brass 
rings were made from 2 -inch brass tubing and were required to 
be finished to -J-iiich wide and threaded 22-pitch. The tubing 
had a Avail of only J^-inch, and as it was impossible to cut off 
and thread the rings in the usual manner in the lathe, the fol- 
lowing simple means were used: A piece of soft wood was 
turned up on centres to fit a length of tubing, as shown in Fig. 
353 finishing one end somewhat smaller than the other, so that 
the tubing could be forced on. Then by driving this wooden 
arbor between the centres, the rings were cut off with ease, as 
shown, without in the least affecting their trueuess. After being 
cut apart the rings would come off the arbor easily. The burrs 
were then removed with a hand-tool, and the rings were threaded 
by holding and locating them in a wood-chuck of the shape 
20 



306 TOOL-MAKING AND 

shown in Fig. 354. This chuck was of soft wood and was 
turned at G so as to allow of its being held in the regular lathe- 




FIG. 353. 

chuck ; then bored out on the face, so that a brass ring would fit 
tightly within it and true itself against the shoulder at H H. 

Four round-head screws at J J J, 
when tightened down against the 
edge of the ring, also helped to hold 
it. The rings were threaded in 
this manner by the usual threadiug- 
tool and fitted to a ping, and were 
removed from the chuck by screw- 
ing the plug in for a few threads 
and pulling the ring out. Some of 
the rings would not fit the chuck 
tightly, but by taking a piece of 
wet waste and wetting the locating 
portion of the chuck, it would 
shrink sufficiently to hold. Any 
one who has ever tried work of 

this kind with the usual means at hand in the lathe, will appre- 
ciate this simple and effective method. 

A DEILL-PBESS JOB. 

The sketch, Fig. 355, shows how an unusual job was accom- 
plished in a simple manner with the best means available, which 
were to say the least not meant for the job. The work was a 
base casting of a two-cylinder pump model, and it was necessary 
to bore two If-inch holes in it in the position shown. The lathe 
wehad was too small to allow of swinging it on the face-plate, 
and the only drill -press in the shop (which was a private experi- 
mental shop) was an 8-inch sensitive drill. So by means of the 




FIG. 354. 



INTERCHANGEABLE MANUFACTURING. 



307 



adjustable cutting-tool shown we did the job 011 the small drill. 
First we drilled and reamed two small holes the required distance 
apart for the centres, a's shown at K, as locating- and truing-points 
for the tit M of the tool R as shown. The tool was fastened in 




FIG. 355. 

the chuck and the work located and clamped to the table and 
the holes finished as shown in the sketch. The tool used for 
this job can be used for a variety of others as well. 

A " STEP-JIG." 

The sketch, Fig. 356, is meant to show one end of a hard rub- 
ber plate which was accurately finished on the side to 7| inches 
wide, 5-J- feet long and to -inch thick. In this rubber plate there 



S OOOOOOOOOOO< 



OOOOOOOOOOOOOOOOOO S' 



FIG. a56. 



were to be drilled fifty-two rows of holes, -J-inch apart and 625 
holes in each row, the size of a No. 60 drill. The number of 
holes in all was 32,500, and each and every one of these holes 



308 



TOOL-MAKING AND 



were required to be accurately spaced, as the rubber plate was 
to be used as a part of the mechanism of a music -box, a steel piu 
being afterward inserted into each hole. There was to be a 
^-inch margin on all four sides of the plate. 

The jig used for drilling and spacing the holes is shown in 
two views in Fig. 357. As the sketch explains itself, very little 
description is required. As shown, there is one row of fifty-two 

holes running in a straight line 
from Jto J, and ^-iuch from the 
holes at the extreme ends of this 
line other holes as shown at 1 1. 
These two holes are for spacing the 
rows of holes in the plate when 
drilling, by drilling the first hole 
^-inch from the end of the plate 
and then locating the jig for the 
next row by inserting the two locat- 
ing -pins K K into and through the 
holes / / and into those coinciding 
in the plate. The holes in the jig 
were spaced and located in the 
universal milling-machine by using 
a small stiff centre-drill for cen- 
tring all holes, and afterward drill- 
ing and reaming them on the sensi- 
tive drill. The manner in which the jig is used and the work 
drilled can be understood from the sketches. The drilling of 
these 32,500 holes took some time, and after each day's work 
on them it was necessary to lay the rubber plate on the planer- 
bed and put heavy weights on it so as to prevent it from warping 
during the night. 

A DEILLIXG JOB IN THE PLAKEB. 

I saw the following combination used to advantage one day 
while looking through a small country jobbing-shop. It consisted 
of a 1-inch drill, a lathe-centre, a dog, and a stick of wood about 
three feet long. They were used for drilling three 1-inch holes 
in the bed of an old planer. The lathe -centre was clamped in 




FIG. 357 



INTERCHANGEABLE MANUFACTURING. 



309 



the tool -post of the planer and the dog fastened to the shank of 
the 1-inch drill. The point of the drill was entered into a cen- 
tre-punch mark in the planer-bed, and the point of the centre en- 








FIG. 358. 

tered into the shank end of the drill. With 
one hand the drill was turned by using the 
stick of wood as a lever, and with the 
other the tool -head was fed down. In this 
manner the holes were drilled. While the use of the lathe -cent re 
and the cross-head as an "old man" was all right, I thought 
that the dog and stick method was rather obsolete, until the 
"boss" of the place told me that they had no ratchet. 



A SPBING- WINDING FIXTUEE. 

Fig 358 shows two views of a simple and handy little spring- 
winding fixture which, as the sketches show its construction 
clearly, requires little description. The body T is a piece of 
finished ^-inch square mild steel, and one end is constructed and 
fitted for winding gauged springs, while the other end is for 
closed springs. The end for the gauged springs has a hole 
through it at Z for the rod L on which the spring M is wound. 
For a gauge for winding the springs, the spring U is used, it 
being located and fastened to the sides of T by the small clamp 
Y. V is a small plate fastened to the body at X, with a guide- 
way at W for the wire. When in use the rod L on which the 
spring is to be wound and the end of wire are fastened in the 
lathe-chuck, the projecting end of the rod entering the hole Z in 
the winder. Then the winder is given a couple of turns around 
the rod, so that the gauger U will have twisted around the wire. 



310 TOOL-MAKING AND 

The fixture is then fastened in the lathe tool -post and the lathe 
started, holding the wire tight by the hand and letting it run 
down the guideway as shown. 

The other end of the winder is used as shown. The screws 
P P and are for adjusting a guideway for the wire which 
passes under the roller Q and is wound around the rod S, as 
shown at R. 

A SOLDEEING FACE-PLATE. 

One of the handiest things around the jobbing-shop is a solder- 
ing face-plate. The number of small, odd, and intricate little 
jobs which can be accomplished with ease by its use is surpris- 
ing. The one we had was fitted up to locate and fasten on the 
face-plate of the Hendey-X orton lathe. It consisted of a disk 
of cast composition about one inch thick and slightly under the 
diameter of the face-plate. After being faced on one side it 
was located and fastened to the face-plate by means of four 
countersunk head- screws which were let in from the back, thus 
allowing of its easy removal when through with it. One of these 
plates should be kept in every tool-room, and one, 1 inch thick, 
will last a long time and pay for itself over and over again be- 
fore being worn out. 

MAKING COLLET SPEING CHUCKS. 

The following kink I found very handy when making collet 
spring chucks of the shape shown in Fig. 359. After finishing 
them in the lathe, leaving, of course, enough stock to lap and 
grind to a finish, face them on an arbor and saw the spring slots 

as shown that is, at the end of each 
slot, as shown at T and V, instead 
of cutting completely through at this 
point, leave a very thin wall of about 
J-inch long at the end of all the cuts. 

Then harden and temper the chuck 
FIG. 359. 

as desired, and after lapping the in- 
side to size, place on another arbor and grind the tapers as re- 
quired. Then take a small, narrow broach and by entering it 
into the slots and hitting it a* sharp blow with a hammer the thin 




INTERCHANGEABLE MANUFACTURING. 311 

wall will break through. This kink I have used to the best ad- 
vantage in shops which had no grinding facilities. When pro- 
ceeding as aforesaid, it was possible to finish the outside and 
tapers to size before hardening without the possibility of the 
chucks running out to a noticeable extent. Of course in work 
of the utmost accuracy this method would not do. But then 
again, work of the utmost accuracy is not accomplished in shops 
where the tool facilities are not up to date. 

A FLAKING-STICK. 

In Fig. 360 is shown a sketch of a little kink which, while no 
doubt old to many, may be new to some. It is a flaking-stick, 
and may be used to produce that circular flaking often seen on 
the inside of watch-cases and often desired for a finish on differ - 



Lead pencil 




Emery cloth ^ 
FiG. 300. 

ent polished small parts. It consists of a stump of a lead-pencil 
and a piece of emery-cloth, as shown, fastening both in the chuck 
of the small drill-press, then running it fast and coming down 
on the work for a second and then shifting it and coming down 
again. The finished effect is fine when a little care is taken to 
move the work evenly. 

DRILLING HOLES IN A HELICAL SUEFACE. 

Fig. 361 shows a drilling fixture, with the work in position, 
for drilling a 500 lot of malleable iron castings of the shape 
shown. In these castings it was necessary to drill twelve 
equally spaced holes c c c around the helical portion. The de- 
sign of the fixture and the manner in which it was used are 
shown clearly and can be understood without description. 

MILLING IN THE DEILL-PEESS. 

Fig. 362 shows the use of a small fixture for milling in the 
drill -press, a portion J out of a small eccentric cam-shaft P. 



312 



TOOL-MAKING AND 



F is the fixture in which the work is located in the hole G. The 
work is located and prevented from turning while being ma- 




FIG. 361. 



chined by a portion of P resting in a turned depression in the 
top of the fixture at H. A hardened taper-pin R, with a flat 
face to bear against the work, secures it, as shown. L is the 
shank of the cutter-holder which is fitted to the drill -press spin- 




FIG. 



FIG. 363. 



die. The cutter K is keyed on and further secured by the nut 
and washer. The stem M of the cutter-holder runs in the hard- 
ened bushing N while the work is being machined. 

A SIMPLE LATHE-CHUCK. 

In- Fig. 363 are two views of a simple chuck used for locating 
and holding a cast-brass ring, while the inside at D D was being 



INTERCHANGEABLE MANUFACTURING. 



313 



bored and the edge E E rounded by the tool at the right. 
There were a hundred of these rings to be done and the -portions 
designated were the only points finished. The chuck proper 
was of cast-iron fitted at A to the lathe-spindle, and the face bored 
out for the work, as shown. The three set -screws B at the back 
were for locating the work true sidewise, while the three around 
the outside at C were for centre -truing and holding it. To fasten 
or release the work it was only necessary to tighten or loosen one 
of the screws C. 



TEIMMING SHEET-BKASS BLANKS. 

The arrangement shown in Fig. 364 was used for rounding 
the edges of sheet-brass blanks -f^ -inch thick and If inches in 
diameter. There were 2,000 of these blanks and they were 
punched in a plain blanking-die. Finishing the blanks by the 
means available in a jobbing-shop was impossible, and for a 




while we thought that we were "up against it"; but one of the 
men. who had done considerable mould making in his time, told of 
a method which he had seen used with great success for finishing 
the edges of "poker-chips." This method was adopted, with the 
result that the job was accomplished with ease and at a very low 
cost. The piece A is fitted to a hole in turret of a small screw- 
machine, with a piece of hard spring rubber B attached to the 
projecting end of the press R. A duplicate of this piece R is 
held in the chuck on the spindle of the screw -machine. The 
rounding-tool is fastened in the front tool-post, while the turn- 
ing-buffer is located in the back one. To machine a blank it is 
held by the fingers against (7, while the piece R with the rubber 



314 



TOOL-MAKING AND 



front B is brought against it by moving the turret up and forc- 
ing the rubber against the blank, which is trued and sufficient 
pressure applied to hold it. The rounding off is then accom- 
plished by the tool, and the blank, is released. The blanks were 
all finished to size in this manner without any trouble. 

A DIE-MAKING KINK. 

Fig. 365 shows a little kink which to the best of my knowl- 
edge is original. It consists of simply taking the upper half of 
a brass door-key and soldering it to the centre of a templet for a 
handle. When the templet is large, as is the one shown, the sol- 





FJG. 365. 



FIG. 366. 



cleriug of the key to it instead of a piece of wire is a great con- 
venience. When the die is finished the key can be removed and 
laid away in one's drawer until required again. 



A SIMPLE SLOTTING FIXTUEE. 

Fig. 366 shows three views of a simple slotting fixture which 
was used to advantage for milling the slots T T in the cast- 
ing shown. There were about 200 of these castings, and they 
were required to interchange. Before slotting they were bored 
and reamed at X X and the hubs were faced. The slotting 
fixture consists of a machine-steel plate into which the cen- 
tral locatiug-stud is riveted ; and two dowel-pins are let into the 
back, as shown. These pins coincide with two holes drilled in 
the stationary jaw of the miller- vise. A gauge-pin in the 
front of the plate, at the right, serves to locate the work as 
required. 



INTERCHANGEABLE MANUFACTURING. 



315 




FIG. 367. 



KEY-SEATING IK THE POWEE-PEESS. 

Fig. 367 shows the method used for cutting a keyway in the 
small cast-iron collar at D. These collars were used in a large 
number ; for that reason the means shown 
were adopted for cutting the keyway. 
The broach is fastened in a holder, while 
the collar A is located beneath the stripper 
of the die-bolster. The stripper and lo- 
cating depression are cut away at the 
front for facing and moving the work. 
The guide is of tool steel, hardened, and 
fits the circular portion of the broach 
snugly. The finishing of the keyways 
in the power-press by the means shown 
proved very satisfactory, far more so 
than by the old way of forcing the broach through under the 
arbor-press. 

HAND CUT-OFF AND FOEMING-TOOL. 

The tool here shown in Fig. 368 was used for the rapid pro- 
duction of small work as sketched in TF, Fig. 271, forming and 
cutting off at the same time. As a rule, all work of this kind 
is done in a turret-lathe or screw-machine. Pieces of the first 
vshape shown in Fig. 373 were produced by the present simple de- 
vice at the rate of 8, 000 a day. 

The tool was composed of two main parts, A the body, Fig. 
269, and B the slide or tool-holder, Fig. 270. Having been planed 
on the various sides it was set up and dovetailed for B to an an- 
gle of eight degrees with the bottom. A hole was then bored and 
reamed at E for the bushing, and hole D tapped for the set-screw. 
A rib was cast up from the base and a hole drilled and tapped 
through its entire length at C for the adjustable stop - sere w H. 
A hole was also cut through the bottom at P as clearance for the 
lower handle T. ' The slide or tool-holder B of cast-iron was then 
machined and fitted to the dovetail in A so as to run freely ; a 
recess was also let in at J for locating the tool or cutter. A flat 



316 



TOOL-MAKING AND 



piece of machine steel, D, fastened by the two screws as shown, 
served as strap for holding the tool. A bushing of tool steel E 
was then finished to the size of the stock to be used and fitted 
tightly within A. This was cut away in front for clearance for 
the tool and left full in the back to steady the side. This was 
then hardened and slightly drawn. A stop-screw ^Twas then 
made which consisted of a long threaded stem to fit the hole ; the 
head was large enough in diameter to serve as an adjustable stop 
for regulating the length of the work. The forming and cutting- 
off tool was made, hardened and drawn, and fitted and held on 
B as shown ; its cutting-face, when the side was advanced, coin- 
ciding with the centre of the hole in the bushing E. The oper- 




FlG. 368. 

ating lever T was then made, the lug J fitting within the hole in 
the slide B, the fulcrum of the lever being held between the two 
lugs projecting down from the bottom of A. A hole was then 
drilled in it for the adjusting-screw or stop N to prevent the tool 
from going too far. Two stiff pull - springs NN were fastened 
by pins in A and B respectively, with sufficient tension to bring 
the slide back when the pressure on the lever was released. The 



INTERCHANGEABLE MANUFACTURING. 



317 



parts were then assembled in the way shown. The rod used 
came in 20 -foot lengths, one end of which entered the hollow 
spindle of the speed -lathe and was allowed to project from the 







O 



o 



m 




f 




FIG. 369. 



chuck almost four feet. This end was entered within the bush- 
ing E ; the lathe was run at its highest speed and the tool held 
in both hands. Pressing on the handle, the slide B moved far 
enough to enable the tool C to form and finish the first end. The 



Side of Slider B 




2 



FIG. 371. 



stop H was then set and the tool moved along until the finished 
end rested against it, when the other end was finished and cut 
off and also the end of the next piece formed, and so on. We 



318 



TOOL-MAKING AND 



cut rods from smallest sizes up to J-incli in diameter in this way 
and beat the other ways by a large margin, the only changes nec- 
essary being to replace bushing E and the cutting-tool C with the 
others. 

xrllLLIKG-JIG FOE THE SPEED-LATHE, 

The jig here shown in Fig. 372 was used for milling the side 
at T of the piece shown in Fig. 373, which was made in the screw- 
machine. After the casting A for the base was planed on both 





FIG. 372. 

sides, the two holes Q Q were drilled for fastening it to the lathe. 
The swivel stud C of machine steel was then made ; the case B, 
of cast-iron, was turned and bored to allow C to move freely 
within it. A J-inch slot f- -inch deep was milled through the 
centre of the top of C and then fastened to the base B by four 
screws. A casting E was planed and the vertical slot for the 
lever F to move in was worked out to fit the lever nicely side- 
wise. An opening was cut away at the farther side, as indicated 
by dotted lines at H, for an outlet sidewise for the lever. The 
hole for the adjusting-screw <7was then drilled and tapped in 
the top and the casting fastened to the front of A by screws, 



INTERCHANGEABLE MANUFACTURING 319 

leaving the slot for the lever in line with the centre of the stud 
C. The lever F was then placed in the slot in C, and a hole was 
drilled through them both for the pin G which was tight in C 
and free in F. The large parts of the jig being complete, the 
piece for locating and holding the work was made. 

The work Fig. 373 was made in the turret-lathe. The groove 
R around the outside of the piece was as near a perfect half -cir- 
cle as it was possible to get it, and about 5 -inch radius. At 
first a piece of machine steel was worked down to the shape 
shown by the outside of K. This was then fastened to the out- 
side of the lever Fby screws and dowel -pins. A hole was then 
drilled in the centre of this at M just the size of the work around 
the body, this hole cutting partly into F as shown, and the shape 
of the small portion of the head worked out, allowing the work to 
rest nicely within it. The distance from the centre of the work 
to the 'centre of the groove R was then found, and the centres 
located on the side of the lever F and two holes drilled through 
the lever and the piece K, cutting half-way into the hole M. 
Two pieces of Stub steel, NN, ^-inch in diameter and the proper 
length, rounded off at the ends, were fastened into a flat steel 
piece so that they would just enter the two holes at N N. 
A round-head thumb-screw W was let in at P, enabling this piece 
to be inserted and withdrawn readily. 

The jig being complete, it was fastened to the lathe crosswise 
and a cutter placed on a mandrel between the centres. The jig 
was then placed so that the work would come central one way, 
and off to the side the proper distance the other way. The lever 
F was dropped down and moved- sidewise out through the open- 
ing H. This left the part for the work to go in clear of the cut- 
ter. The work was then inserted and the lock-pins N N w r ere 
thrust in, thereby binding the work securely. The lever was 
then re-entered into the slot H and raised to a height sufficient 
to mill the work to the proper depth, when the top of the lever 
encountered the top screw J. We did quite a variety of different 
milling and cutting of this kind with this jig. 



320 



TOOL-MAKING AND 



JIGS AND FIXTURES FOE ADJUSTABLE STOPS AND 
SPINDLE-BACKS. 

Figs. 374 and 375 show in two views an adjustable stop com- 
plete, as used on drill-press spindles. As shown, it consists of a 
casting with the centre hole A bored and reamed to fit the spin- 





FIG. 374. 

die of the press at the upper end. It is also drilled at each end 
for a screw and slotted at D. The screw C is for tightening 
it on the spindle. The adjustable stop-screw F consists of a 
knurled screw F and a jam-nut, as shown. For the machining 
and finishing of the casting three operations were necessary. 

For the first, that of boring the centre hole A and facing one 
side at B, the special chuck shown in the two views in Fig. 376 




FIG. 376. 

was used. It consists of a casting G of the shape shown, which 
was first chucked and a hole bored through it at L. This hole 
was then enlarged and threaded at H, as shown, to fit the spindle 
of the turret-lathe. It was then removed and the face milled 
and cut away as shown that is, on the sides K K and J and a 
straight cut to the depth shown through the face at 1 1 made. 



INTERCHANGEABLE MANUFACTURING. 



321 



A hole was then drilled and tapped for the clamping -screw P, 
which was reduced at one end and fastened within the clamping - 
jaw M, as shown, the plate keeping it in position. The chuck 
was then screwed on to the spindle of the turret-lathe, a piece of 
steel placed between the jaws M and N at each side, and the 
screw P tightened so as to clamp them securely. The two jaws 
were then bored to the diameter and depth shown, the radius 
being the same as that of the largest circular diameter of the 
casting Fig. 375, and in depth so that it would project outside 
of the chuck enough to allow of it being faced. All this being 
done, the chuck was finished and ready for work. 

When using the chuck the casting Fig. 375 was clamped be- 
tween the jaws Jf and N, and the hole A was bored and reamed, 
by means of the turret-tools, and faced by a tool in the tool-post 
of the slide-rest. As will be seen, the chuck is suggestive for a 
number of different jobs on odd-shaped castings, as it is easy and 
inexpensive to construct, and also rapid in 1 andling and produc- 
tion. It is a type of chuck used quite extensively in the brass- 
shops, where odd-shaped castings, for various purposes, such as 
unions, etc. , are made in large quantities. When a number of 
different-shaped pieces in number sufficient to allow of the nee- 



f=v 



* 



@ 



o 



r 



FIG. 377. 



essary expense are required to be bored and reamed to a given 
size, the means shown are the best for producing them. The 
chuck shown can be so constructed, by changing it to suit, as to 
allow of pairs of different-shaped jaws being inserted in place of 

the ones in use. The way to do this is to finish the face of the 
21 



322 



TOOL-MAKING AND 



chuck with a stiff projection at each side, and dovetail the jaws 
into them, one of the jaws, of course, being adjustable. 

For the next operation on the casting, that of drilling the 
holes at C and ^"respectively, the drill- jig shown in Fig. 377 is 
used. It requires no description to be understood. 

For the last operation, that of slotting the casting at Z>, a sim- 
ple little fixture for use in the milling-machine is shown, and as 
the two views of it with the work in position, shown in Figs. 378 
and 379, are very clear, very little description is necessary. An 
angular-shaped casting A is first planed and finished as shown, 





FIG. 378. 



FIG. 379. 



the part B as the base to rest squarely within the milling-ma- 
chine vise. A machine-steel stud C is then turned to fit the cen- 
tre hole A in the casting, Fig. 375, and reduced at one end so as 
to shoulder against the back of the fixture B, and riveted tightly 
within it at D, as shown. The pin is for locating the casting 
squarely on the fixture. A slot is cut through the top in line 
with the centre of the stud C and running partly through it, as 
shown. This in order to get the slot in the centre of the cast- 
ing, that is, central with the hole A, Fig. 375. In operation 
the casting is placed on the fixture as shown, and forced against 
the pin E. Both fixture and casting are then clamped in the 
miller-vise, and the cutter G entered into the slot. When the 
casting is milled, it is removed and another substituted, and the 
operation repeated. This little fixture is all right, as it allows 
of the slotting operation being accomplished uniform in all of the 
castings, giving them a neat and mechanical appearance when 
finished, and is far superior to the usual way of doing simple 
jobs of the kind shown, namely, setting the casting central to the 
eye, and then going ahead, with the ultimate result that there 
are not two alike. 



INTERCHANGEABLE MANUFACTURING. 



MILLING SPINDLE-KACKS. 

In Fig. 380 is shown, in three views, a fixture which is used 
for milling drill-press spindle-racks. And, as it is as practical 
a device as could be designed for use in the regular milling- 
machine, it is worthy of interest, handling, as it does, sixteen rack 



K K 



PLAN VIEW 




s 


I 


1 


. 


~ 
, 


" 


_ 


i 


^ 


~-> 





_ 


_ 


i 


J 

J 


^_ 
' 


i. 
-c 




M 










M 








o 
M 








. 



M 


3 


: 


c 
M 





c 


--.', 


( >- 




' 




-- 


-j .- 


H ) 




xA 


-i .:: 


- - 


- 


i 




ft 


c 


, 


': 






Z 


r 


2; 


i 


t 


7 


"" 


: 


f 


." 


" r 


K 
K 






K 
K 






K 
K 






K 

K 






K 
K 






K 
K 





END VIEW 



FIG. 380. 

blanks at a time. In design it is both simple and compact and 
is so constructed that a boy can operate it successfully while 
running another machine ; as when the cutter is set, the time nec- 
essary to allow of the cutters running through the entire sixteen 
blanks can be utilized in looking after a different operation in 
another machine. 

In constructing the fixture a flat casting of the shape shown 
at If was first secured in appearance resembling a die-bolster 
was planed smooth on the top and bottom, and the tongue J 
fitted to the slot in the milling-machine table. While planing 
the tongue a cut was taken off each side, so as to have them 
square. The casting was then transferred to the milling machine. 



324 TOOL-MAKING AND 

when the four rows of holes, sixteen in number, for the dowel- 
and locatiug-pins '1 and J J were drilled. These holes were for 
locating the rack blanks, which had been previously milled to 
size, and the four holes in each drilled in a jig so that they were 
exact duplicates of each other. In drilling the holes in the cast- 
ing // it was strapped on an angle-plate, facing the spindle, 
which was in tnrn clamped to the extension plate on the milling- 
machine table, taking care to get the casting H fastened so that 
the tongue <7was parallel with the table. The first row of holes 
was then drilled by first using a small centre-drill and spacing 
the holes by means of the dial on the feed-screw of the table, and 
then drilling them all in the same manner, repeating the opera- 
tion until the four rows of holes for dowel- or locating-pins / / 
and J J were drilled. 

In the spacing of the holes, so as to get them in the relation 
to each other, as shown, great care was taken so as to have them 
coincide perfectly with those drilled in the racks, as these pins 
locate the blanks square on the fixture when in use. Sixty-four 
small pins were then cut off to the length shown, and rounded at 
one end ; they were made of Stub wire and driven tightly into 
the holes drilled in the fixture, and an easy fit in the holes of the 
rack blanks. 

The small clamps shown at K K, of which there were thirty- 
two, were then made to the shape shown, by taking four bars, 
long enough to get eight out of each, and milling them to the 
shape required, after which they were cut into sections, which 
were the clamps shown. The clamps were then drilled for the 
screws L as shown, and sixteen fastened at each side of the fixt- 
ure in the position required, so as to grip tightly the ends of the 
blanks and keep them flat and square on the fixture. The heads 
of all screws were case-hardened. 

The various parts of the fixture were then assembled, and the 
fixture complete strapped on the milling-machine table by means 
of bolts through the ends at 1 /, and with the tongue S in the 
centre slot. The sixteen rack blanks were then located and fast- 
ened on the fixture by fixing them on the pins 1 laud t/t^and 
the clamps tightened as shown on the blanks 31 in the plan view 
of the fixture in Fig. 380. This figure shows the blanks partly 



INTERCHANGEABLE MANUFACTURING. 



finished, the last one being off to show the pins for locating them. 
Two cutters of the pitch required were used, and the table of the 
miller raised so that the full cut would be taken. The feed was 
then put on, and 'the cut taken through the entire sixteen blanks, 
when the table was run back to the starting-point, moved over 
the required number of thousands, and the cut repeated, and so 
on, until the entire sixteen blanks were finished. They were 
then removed and another lot located and fastened in the same 
manner, and the operation of milling repeated. 

This fixture overcomes the difficulties which are usually met 
with when milling one rack at a time, by holding it in the mill- 
ing-vise. As when it is done in that manner it is necessary to 
mill all sides of the blank perfectly square with each other, in 
order to get them to lay flat while being cut, while by the use of 
this fixture, as shown, it is not necessary to be so particular, as 
the blanks are held by means of the clamp at either end, and 
located squarely and in line with each other by the pins shown. 
Another thing, the setting is easy to accomplish, as it entails no 
adjustment of the parts. 

JIG FOB DRILLING SMALL THREAD DIES. 

Some years ago I had a job of making one hundred small 
thread dies for screw -machine work. To have drilled them in 





FIG. 381. 



FIG. 382. 



the regular way would have taken a great deal of time and made 
them very expensive, so I made the jig shown in Fig. 382 for 
the purpose. 

First, I turned and finished a bar of steel to exactly the right 
size for the dies and then cut off the blanks, being particular to 



326 TOOL-MAKING. 

get them all the same thickness and also to chamfer the corners. 
Fig. 381 shows the die blanks, which are ^-inch diameter. Fig. 
382 shows two views of the jig, the top and a cross section. The 
jig was made in the shape of a round box. B is a piece of round 
machine steel turned and finished as shown with a thread of 10- 
pitcli cut at F which was cut loose in order to work the jig rap- 
idly. At the same time the seat for the blanks was turned out 
at C so that they would just tit in without play. A hole was 
then bored through at D to give clearance when the drill came 
through and also to let the chips out. The jig proper A was a 
piece of round tool steel chucked and finished all over in the way 
shown. The centre hole was drilled at the same time, and a cir- 
cle was struck to drill the other four holes by. The outside was 
heavily knurled to give the operator a good grip. All holes were 
reamed and slightly countersunk to allow the drills to enter 
freely, when the work was carefully hardened and drawn, being 
then ready for work. The blanks were laid in at C, the cover A 
was screwed down, and the holes all drilled, and another die in- 
serted, and so on with them all. It was surprising how quickly 
the dies were made by the use of this jig. 



CHAPTER XXII. 

Special Tools, Fixtures, Devices, Arrangements, 

Contrivances, and Novel Methods for Metal 

Working. Continued. 

A MACHINE FOE TWISTING COEKSCEEWS. 

THE machine here shown was made for twisting wire cork- 
screws of the type shown in Fig. 383. The wire before the twist- 
ing is shown below the corkscrew. It is " looped " at one end 
and bent, while the other end is pointed. The cutting off of the 
length of wire and the pointing of one end are accomplished in 





FIG. 383. 

one operation by means of two simple tools in the monitor ; the 
tool used for pointing being a " needle " box- tool, and the one 
for cutting off a "choppiug-tool." The second operation on the 
wire lengths, that of bending and forming the "loop, "is done 
by hand, with a simple bending fixture not of sufficient interest 
to show here. 

The drawings, Figs. 384, 385, and 386, of the twisting-machine 
show its construction and little description will be necessary. 
The machine consists of, first, a body or main casting on which 
are four standards for bearings for two shafts. The pulley, 

327 



328 



TOOL-MAKING AND 



clutch, and small driving-gear require no explanation. The wire 
is clamped between two jaws H H, Fig. 384, the upper one of 
which is raised or lowered by the handle and two gears A A turn- 
ing right and left screws. The mandrel or forming-spindle X is 
of tool steel finished to fit easily within the sleeve K, which in 
turn is fitted and keyed to turn with the slide, back and forth 
within the main spindle V by a key at D. A handle at Z fast- 
ened to the forming -mandrel by the set-screw W keeps the man- 
drel stationary, by a round-headed pin entering the back at Y, 
while the sleeve with the main spindle rotates and twists the 



Spindle Gear 




FIG. 384. 

wire. This pin is located in the bracket T, with a spring at the 
back at S and a handle at R to allow of its being forced back 
when the mandrel -lever is to be turned. 

When the machine is in use the work is located and clamped 
between the two jaws H H, with the pointed end lying in the slots 
L and M of the sleeve K and the spindle V respectively, and the 
handle of the forming -mandrel located and held by the -pin T, 
Fig. 384. The clutch -lever is then pulled back and the spindle 
V and the sleeve K rotate while the forming-mandrel remains 
stationary, thus twisting the wire around the mandrel to the 
shape shown in the half -tone. The clutch -lever is then pulled 
out and the machine is stopped when Z is released and turned 



INTERCHANGEABLE MANUFACTURING. 329 

toward the left, thus drawing out the sleeve and mandrel, leav- 
ing the finished corkscrew so that it can be removed by loosen - 




FIG. 385. 

ing or raising the upper jaw H. The mandrel and sleeve are 
then slid back in position, another piece of wire is located, and 
the operations are repeated. 

A SPECIAL TOOL FOE CUTTING LAEGE FIBEE- 
WASHEES. 

In a shop in Brooklyn, where they make large embossing 
presses, the rollers of which are made up of fibre-washers forced 
on to machine-steel shafts, I saw a tool for cutting the washers 
from the sheets. This is shown in Fig. 387, and the manner of 
using in Fig. 388. In the shop referred to, two sizes of washers 
are used ; one size 15 inches in diameter with 4-inch hole, and 
the other 18 inches in diameter with 5 -inch hole. The thickness 
of the fibre board is -inch. 

As shown in Fig. 387, the tool consists of a 1-inch drill with 
a cutter-head beam B let through a slot as shown, and fastened 



330 



TOOL-MAKING AND 



by two screws. C and D are the cutter-heads, which are finished 
to a good sliding fit on the beam, and / and If the cutters, which 
<ire hardened and tempered and let into split seats in the, cutter- 




FlG. 38(5. 

heads and fastened by the screws G. The cutting-tools are a 
trifle less than yL-inch in thickness and are given sufficient back 
and side clearance to allow them to cut freely. 

Fig. 388 shows how the tool is used. A piece of 1^-inch 
planking is fastened to the drill-press table, and the table is 




FIG. 387. 



clamped in a central position. A small pin forced into the 
planking at the right serves as a gauge for locating the fibre be- 
neath the drill and also to space the washers evenly. The drill- 



INTERCHANGEABLE MANUFACTURING. 



331 



shank is fastened in the chuck in the drill-spindle and the tool is 
rotated at about forty turns per minute. The drill cuts first, and 
as soon as it has passed through the fibre and entered the wood 
the inside and outside cutters begin to cut. A slight pressure is 
all that is necessary to make the tools cut, the shavings curling 




FIG. 



up nicely, and as soon as they have passed through the fibre a 
quick raise on the feed-lever causes them to pull free and clear 
of the work. As will be seen, the tool cuts the inside and the 
outside of the washer simultaneously, and as the insides are 
used as washers for smaller-sized rolls two washers really are 
produced at once. 

AN UNUSUAL AND SPECIAL JOB OF TOOL-MAKING. 

Figs. 389 and 390 show a rather unusual job of tool-making, 
and Figs. 391 and 392 the manner and means used in its accom- 
plishment. The job in question was the making of a tap and die 
for cleaning out and " sizing " a patent pipe union, the parts of 
which were of brass and were cast. The thread required in the 
union was a 1^-inch diameter, ^-inch square thread, and instead 





of one continuous thread, five were required. Thus the pitch of 
each thread was If -inch. This will be understood from Fig. 389, 
in which the tap is shown as finished. A is the first thread, B 



332 



TOOL-MAKING AND 



the second, C the third, D the fourth, and E the fifth. L L are 
the spiral flutes, of which there were five. 

The tap was made first. The means used are shown in Fig. 
391 and consist of a small face-plate fitting the lathe-spindle, a dog 
and a driver. The face-plate had five holes drilled and reamed 
at equal distances apart on a radius true with the live centre 
of the lathe. This was done on the dividing-head of the univer- 
sal milling-machine, first indexing for five, and centring with a 
stiff centre-drill, then drilling and reaming to size. A driver of 
tool steel was then turned up as shown, with a stem Q threaded 
for the nut V, and turned to fit snugly the reamed hole in the 
face-plate and to shoulder at H. 

The dog T was also of tool steel, and was finished, as shown, 
with a broached hole to fit the square on the shank of the tap- 




FRONT VIEW e^CTIOM 
ACEPLATE AND 
RIVER 



FIG. 391. 

blank snugly, so that there would be no lost motion. A set- 
screw was also let in, as shown, to insure the positive locating 
and drive. 

The manner in which the tap -blank was held and driven on the 
lathe-centres when cutting the threads is shown clearly in Fig. 391. 
The first thread was cut by locating the driver in the first hole in 
the face-plate. Then the second thread B was cut and finished 
by transferring the driver to the next hole. Thus in succession 
the entire five threads were cut and the tap finished accurately. 
The dog was not moved from its position on the end of the blank 
until the tap was cut. As w r ill be seen, the side\)f the dog T 
which bears against the driver is hollowed out to the radius of, 
the drive-stem, thus giving a wide bearing surface and insuring 
a positive drive. A piece of belt lacing, tied around the dog- 



INTERCHANGEABLE MANUFACTURING. 



333 



stein and driver, prevented backlash when the tap-blank was re- 
volving free. In doing the cutting a tool accurately ground to 
size and clearance was necessary. After being cut the tap was 
" backed off" slightly and then fluted on the milling-machine, 
finishing the flutes, five in number, on a spiral, so that the cut- 
ting-faces of the thread sections would be at right angles with 
the pitch, as shown. 

After being hardened, the cutting-head was ground, grinding 
the tap-taper for half its length. Not much lead was necessary 
as the tap was to be used for cleaning and sizing only. 

The manner in which the die was finished can be understood 
from Fig. 392. The die-blank was 1^ inches thick by 3 inches in 




FIG. 392. 

diameter. After the outside had been turned to the required size 
the die-blank was left on the mandrel on which it had been 
turned, and w r as set up in the centres of the universal miller. 
A cutter was then used to mill five equidistant semicircular 
grooves around the outside, as shown at 0. Next, another small 
face-plate, fitting the spindle of the lathe in which the tap had 
been cut, was bored and finished with a seat at L L for locating 
the die-blank true, and with clearance at B B for the thread- 
tool. A hole was then drilled in the face-plate so as to be dead 
true with the half-round grooves in the die-blank, and a Stub 
steel pin driven into it, as shown at P. The diameter of this 
pin was exactly the same as the grooves in the die-blank. Thus 



334 TOOL-MAKING AND 

the central locating of the die-blank on the face-plate was insured 
by the locating-seat L L, and the spacing of the threads by the 
half-ground grooves and the indexing-piii P. The clamping 
arrangements require no description, as the drawings show them 
plainly. 

To cut the threads the die-blank was located on the face-plate, 
as shown, with the pin P in the first groove 0. Thus the first 
thread was cut. Then the clamps were removed and the die- 
blank relocated at the second groove, and the clamps retightened 
and the second thread cut. These operations were repeated un- 
til the entire five threads had been finished to within a shade of 
the diameter of the tap. The die was then removed and sized 
with the tap. 

By reverting to Fig. 390 the reader will see how the die was 
finished. H H H II are holes drilled at an angle with the die- 
face, so as to have the cutting-faces of the threads at approximately 
right angles with the pitch. The die was left solid and hardened, 
and the shrinkage resulting in it allowed of the parts cleaned 
and sized by the die being an easy fit within the parts finished by 
the tap. 

SPECIAL ENGKAVIXG--MACHIXE. 

The machine represented herewith in Figs. 393 to 396 was de- 
signed by the writer for the special purpose of engraving moulded 
composition checks, which are used for a number of purposes in- 
stead of money, in sets of exact duplication ; this being impossi- 
ble by the hand method, which was the means used before this 
machine was designed. 

As these check sets are produced in large quantities and as 
there is always a steady demand for the best quality, the use of 
the machine here shown proved a great factor in reducing the 
cost of their production. Its use also allowed of the attainment 
of results in duplication which were formerly impossible. 

The design and construction of this machine is such as to 
allow of its adoption for a multitude of other uses besides the 
special one for which it was used. A few of the uses to which 
it may be adapted by mechanical readers are : the backing off of 
small gear, ratchet, and other cutters for clock and watch work, 



INTERCHANGEABLE MANUFACTURING . 



335 



the turning of odd-shaped punches, wherever they -are used in 
large numbers, turning elliptical punches and dies, either 
straight or taper, and the finishing of small circular cams and 
eccentrics. A number of other uses will suggest themselves to 
the practical man. The writer has already adapted the princi- 
ple of this machine, with slight modifications, in a new machine 
to be used exclusively for backing off cutters for watch and clock 
pinions. 

As the three views of the machine show clearly its design and 
construction as well as its use, we will confine ourselves to merely 
pointing out its main features. The construction of the head 




L JS^ 



FIG. 3 1 J3. 

requires no description whatever, as it is shown clearly in Fig. 
396. Eeference being made to the three views: the machine 
consists of the base A, on which the bearings B B for the head- 
spindle and those at C C for the cam-spindle are cast in two legs 
to which the base is fastened and the head and slide-rest. In the 
front- end view, Fig. 394, the check is held in the spring-chuck G 
and the tool V set to as shown. The gear Kon the cam-spindle 
is the same size as the one at Q on the head-spindle and is driven 
by the intermediate gear J. The cam R is of tool steel and is 
hardened and lapped to a smooth finish. The engaging-stud T 
is also of tool steel and is driven into the tool-slide Q as shown, 



336 



TOOL-MAKING AND 



and the pointed end rests against the cam R. The spring B B 
at the front is of sufficient strength to keep the engaging-stud T 
tightly against the cam face. 

When the machine is in use, a check is held in the spring- 
chuck G and the tool U set as shown. The machine is then 




FIG. 394. 



started and the tool fed np to the work by turning the cross-slide 
handle Z. The cam R revolves at the same speed as the work 
and the slide W is moved in and out accordingly, the tool pro- 




FIG. 395. 



ducing the results shown. As everything else can be seen and 

understood from the drawings no further description is required. 

In Figs. 397-403 are shown seven samples of checks which 

were engraved in this machine. For the one shown a,t A a tool 



INTERCHANGEABLE MANUFACTURING. 337 



with four points was required ; for the one shown at B a tool 
with three points ; while for C D E and G tools with two points 




FIG. 396. 



were used, and for F one with one point. For each different 
design a special cam was made. With the machine a boy 







FIG. 39T. 



FIG. 398. 



FIG. 399. 



FIG. 400. 






FIG. 401. 



FIG. 402. 



FIG. 403. 



turned out four checks a minute, while an engraver working by 
hand could only turn out one every minute. 

SPECIAL CAM-MILLING MACHINE. 

Fig. 404 shows a plan of a special cam-milling machine built 
for milling certain cams used on a printing-press. E is the cam 
as milled. It is in the form of a stepped cone and is fastened to 
the spindle B by the nut F. G G are the standards in which the 
spindle B is rotated and reciprocated endwise by means of the 
gear C and the master-cams A A. D D are two lugs projecting 
up from the base of the machine in which are turn rollers which 
contact with the cam surfaces. 

K K are the standards for the milling-spindle, L a cone pulley 

22 



338 



TOOL-MAKING AND 



driven by belt, M a worm which turns a worm-gear on spindle 
N, H the milling-cutter, I a draw-in spring-chuck, and </the 




FIG. 404. 

driving-spindle. T is the hand-wheel for feeding in the cutter 
H. The pinion on the worm-gear shaft -ZV drives gear Q, and 




FIG. 405. 

pinion E drives the large gear C on the cam -spindle. Thus the 
milling-cutter is rotated at a high speed and the work E very 
slowly. 

CHUCK FOE TURNING ECCE^TEIC KIN"GS. 

Fig. 405 shows a chuck used for turning eccentric brass rings 
of the shape and section shown at A in the engraving. They 



INTERCHANGEABLE MANUFACTURING. 339 

were to be bored out, faced on both sides and turned on the 
periphery, all dimensions being made to gauge so that the pieces 
would interchange. In order to turn out the work at a profit it 
was necessary to design and build a few fixtures for the handling 
of the work. Two chucks were made for this purpose. The 
first, which held the ring while the eccentric hole was being bored 
and one side faced, was of no special interest. After this opera- 
tion the key way at B was machined with the aid of a simple slot- 
ting fixture. 

The chuck that was employed for the last operation, that of 
turning the periphery and facing the remaining side, possesses 
several features of general interest that may be adapted to other 
work of a similar nature. This chuck is shown in Fig. 405 hold- 
ing one of the rings in position to be operated upon. The body 
of the chuck C was threaded to screw on to the spindle of the 
lathe, and carried on its face three expanding and contracting 
segments for truing and holding the ring, one of them being pro- 
vided with a key which fitted the keyway B for locating and 
driving the ring. These segments were held in place on the face- 
plate by three shoulder-screws D I) D which passed through 
radial slots, thereby allowing the segments an in-and-out move- 
ment across the face of the chuck. This expanding movement 
was imparted to the segments by means of the knurled-head ex- 
panding-screw E, which was tapered slightly so that the ten- 
dency when they were tightened or expanded would be to force 
the work against the face-plate. The clamping surfaces were 
eased off so that only about an inch of each would bind against 
the work. 

The manner in which the chuck was used and the work ma- 
chined was as follows : The stud E being screwed outward by 
grasping its knurled head, the segments were contracted. Then 
the ring was located against the face-plate with the key in the 
segment fitting the keyway B. The expanding-stud was then 
screwed in and the segments in expanding forced the work tightly 
against the face-plate and held it securely. It was then a simple 
matter to turn the periphery to the required diameter and face 
the side, after which the segments were contracted by unscrew- 
ing the expander, the finished piece was removed, and another 



340 



TOOL-MAKING AND 



located ready for machining. As will be understood, the ma- 
chining of the rings with the usual means handy around the shop 
would have been difficult and would have consumed much time ; 
while by this method there was no time lost and the complete in- 
terchangeability of the rings when finished was guaranteed. It 
was surprising how easily and rapidly the rings were located and 
removed and how tightly they were held. As the brass castings 
from which the rings were finished were not of the best quality, 
a cut of considerable depth had to be taken, thus putting con- 
siderable strain on the segments. 

CHUCKIMI FIXTUBE FOE ECCENTBIC STBAPS. 

While none of the tools shown in the following are of very 
unusual construction, they are of interest because of their sim- 
plicity and their value in producing rapidly and interchangeably 
the required parts. 

The first fixture is shown in two views in Figs. 406 and 407. 
It is used in the boring and tapping of the hole A in the eccen- 




FIG. 408. 



FIG. 407. 



trie strap B. The piece is of cast-iron, and the operations per- 
formed previous to the one mentioned are the milling of the 
faces of the two parts of the strap, the drilling and tapping of 
the two holes in the lugs for cam-screws, the boring of the 4^-inch 
hole, and the facing of the two sides. The hole is bored and the 
two sides faced at the one handling by strapping the work on 



INTERCHANGEABLE MANUFACTURING. 



341 



the lathe face-plate so that the lugs rest on parallels which are 
thick enough to allow of using a "hook" tool for finishing the 
side nearest the face-plate. 

The fixture for boring and tapping the hole A as shown in 
Figs. 406 and 407 is very simple and requires but little descrip- 
tion. It consists of an angle-iron, which is bolted to the lathe 
face-plate; a " locator," and two clamps. The "locator" and its 
use are shown in the plan view. It is fastened to one face of the 
angle-iron by means of two flat-head screws so that the strap B 
will be located central and true ; the planed surface by which the 
piece B is joined to the other section resting squarely against 
the face-plate. As will be seen, the use of this fixture insures 
the locating and finishing of the hole A centrally, and in lii e 
with the large hole in the strap. 

TWO NOSE-CHUCKS FOE ECCENTRIC CAMS. 

In Figs. 408 and 409 we have two views of a chuck used for 
the first operation on an eccentric cam. It is of cast-iron, bored 
and threaded at the back, and bored eccentric at the front for 





FIG. 408. 

the stem I of the cam. This eccentric hole was laid out with the 
height-gauge and "buttoned," and then indicated on the lathe 
face-plate and bored. A pin J locates the cam properly and as- 
sists in driving it while the surfaces K and L are being ma- 
chined. Two set-screws equipped with brass ends are used at M 
to secure the stem in the chuck. 

The next operation on the cams is the milling to size of the 



342 



TOOL-MAKING AND 



portion indicated at N. For this a simple little device (not 
shown) in the form of an angle-iron with a seat -upon which to 
clamp the machined portion of the cam is used. 

For the third operation, which is the last, the chuck shown in 
Fig. 410 is used. As will be seen, this is of much the same de- 




Fl(i. 410. 

sign as the other, except that it is equipped with a "locator" 
which fits the milled channel N. Two set-screws fasten the work 
in the chuck. 

It is obvious that with these two chucks the production of 
cams that are interchangeable is not difficult, and at the same 
time it is possible to machine them rapidly. 

FIXTURE FOR CHUCKING GASOLINE-ENGINE 
CYLINDERS. 

The chuck shown in Figs. 411 to 413 contains some points of 
interest that may be adapted to the rapid production of any work 
of a character similar to the pieces for which the fixture was de- 
signed. The casting for holding which this chuck was made 
was, as will be seen, of rather unusual shape. It formed a triple 
cylinder for a high-speed automobile engine which was being 
manufactured in large numbers. It had three cylinders B B B, 
which were required to be bored out and reamed to size at C, 
turned on the outside at E, and counterbored and tapped for 
plugs at D. The portion indicated by the letter A was the hub. 
The centres of all three cylinders had to be on the same plane 
and spaced so as to form exactly the same angle with each other. 



INTERCHANGEABLE MANUFACTURING. 343 

The construction and use of the chuck will be seen by refer- 
ence to the three views shown in the illustration. G is a face- 
plate, turned and finished to screw on to the lathe spindle and 
channeled down the face to allow of locating the angle -plate H, 
which was fastened to it by the cap -screws K K K. The hub of 
the casting was first held in another chuck and bored out on the 
inside and finished on the outside to gauge. This preliminary 
w ork formed the basis for the accurate accomplishment of all the 
succeeding operations. The work was then located centrally 




FIG. 411. 

on a boss F formed upon the bracket H so that the three cylin- 
ders would come approximately central. For clamping, the three 
straps N N N were used ; while the indexing was accomplished 
by plug K, Fig. 412, whose locating part was hardened and 
ground to fit the finished bore of the cylinder, and also the 
reamed hole in the lug J. 

When using the chuck, a casting was first clamped somewhat 
loosely upon the angle-plate H, being located centrally by the 
stud F. A plug, which for a distance along its length fitted 
the reamed hole in the lug J and for the rest of its length fitted 



344 



TOOL-MAKING AND 



the cored holes in the cylinders loosely, was inserted, through the 
lug, into one of the cylinders. The clamps were then tightened 




FIG. 412. 



and the machining proceeded. First the outside of the cylinder 
was turned at E E to gauge, after which the steady rest was 




FIG. 413. 



brought up and adjusted so that the finished portion ran true 
within it. This was followed by the boring and reaming, which 



INTERCHANGEABLE MANUFACTURING. 345 

was done by first using a bar with an inserted cutter, then a 
shell-rose reamer, and finally a one-bladed reamer for finishing. 
After reaming, the counterboring and tapping were done. Now 
the clamps were loosened and slid back, the work removed from 
the angle-plate the temporary ping having, of course, been first 
removed and the casting relocated with the finishing-cylinder 
in line with the lug J. The plug K was then inserted, through 
the lug, into this cylinder, which it fitted perfectly. The set- 
screw M was tightened, thereby holding the plug securely in 
place, after which the clamps were secured and the second cylin- 
der was bored, reamed, counterbored, and tapped as had been 
done with the first. After this the same method of procedure 
was followed for finishing the third, or remaining, cylinder. 

SPECIAL MILLING-. AND DBILLING-JIGS. 

Fig. 414 shows a casting which formed part of a clutch for a 
perforating machine. The jigs shown in Figs. 415, 416, 417, and 
418 were used in its production. The castings were 44- inches 
in diameter by 3-j inches long, with a cored hole in the centre. 




FIG. 414. 

The work to be done consisted, first, of boring and reaming the 
hole A A to 2 inches, facing both sides, turning the outside, and 
cutting in the groove E E. For this plain lathe no fixtures were 
necessary. The further operations required were: Boring the 
hole B for the sliding clutch-pin, milling the slot D D for the 
feather C, and drilling the hole F. 

For drilling the hole B the jig Fig. 415 was used. The cast- 
iron body or base is machined on the bottom to bolt on to the 
table of the drill -press. This body casting has a stem projecting 
up from the centre which is turned to fit the hole A A in the 



346 



TOOL-MAKING AND 



work, and is tapped at the top to admit the bushing-plate clamp- 
ing-screws. There is a machined seat for the work to locate On. 
The body of each clamping-screw enters the locating-stem for 
a certain distance to insure the locating of the centre of the 
hole B. 

The milling of the slot D D in the casting and the drilling 
of the hole F were accomplished by the jig shown in Figs. 416, 




FIG. 415. 



417, and 418 ; Fig. 416 showing it as used for the milling of the 
slot, and Figs. 417 and 418 when drilling the hole F. 

The fixture consists of an angle-plate with a central locating- 
stud fitting the centre hole of the work. This stud is tapped for 



Front or Pace View 



Cutter 




FIG. 416. 

the fastening-screw. To locate the work on the jig so that the 
slot D D when milled will be properly located, the hole B in the 
work is utilized, a steel pin in the jig fitting it. This pin is 
made to fit the hole in the work and two holes in the fixture easily 
to allow of its removal and re-use in locating the work in position 
for drilling the hole F. To expedite the locating and fastening 



INTERCHANGEABLE MANUFA CTUR1NG. 



34V 



of the work on the fixture and its removal when milled a clamp- 
ing-washer with a section cut out is used, thus allowing of merely 




loosening the screw and slipping out the washer when removing 
the work. When in use the fixture is located on the miller-table 
and held by two bolts, the tongue fitting the central groove of 
the table. 

The manner in which the hole F is drilled is clearly indicated 



FIG. 418. 



* 



1 



by Figs. 417 and 418. As will be seen, all that is necessary to 
allow of using the fixture for this operation is the locating of the 



348 



TOOL-MAKING AND 



stud in B and the locating and fastening of the bushing-plate 
/ 011 the top of the body casting. G G are dowels, II a cap- 
screw, and J a bushing. As the hole has only to run into the 
centre hole A of the work, the presence of the screw W does not 
interfere with the drilling. Although the fixtures are very 
simple and inexpensive they are great labor savers. 



A SET OF JIGS FOE MILLING AND DRILLING. 

In Fig. 419 we have three views of a cast-iron punch-head 
used on gang eyelet-perforating machines. These punch-heads 
are required to be machined accurately so as to be interchange- 
able, and are handled during the course of manufacture entirely 
by jigs. While the work done by the use of these jigs is very 
accurate and is accomplished rapidly, none of them are intricate 
or expensive. The piece shown is about ten inches long over all. 




FIG. 419. 

The punch-head consists (not counting screws) of four parts: 
The head proper, of cast-iron; the back-plate J 7 , of machine 
steel ; the punch-key J, of brass ; and the gib at C, of machine 
steel. Leaving the smaller parts, we will take up the machining 
of the head proper. 

The work required to be done on the punch-head consists of 
milling all sides square and true, milling the dovetail B B and 
the gib-way G, milling the angular-formed face D J), drilling 
and reaming the long central hole E E, drilling four holes II HOT 
fastening the back-plate, two holes for fastening the brass key, 
one hole for the gib -tightening screw F and another clearance - 
hole for the gib -pin G. 



INTERCHANGEABLE MANUFACTURING. 



349 



The castings for the heads before machining were square all 
over except for the dovetailed and gib surfaces, which were 
roughly cast. 

The first operation was accomplished on a large milling-ma- 
chine by means of a supply fixture, and a large inserted tooth- 
milling cutter handling ten castings at a time. This fixture is 
not illustrated. 

For milling the dovetail and gib- way the jig Fig. 420 was 
used. This accommodated eight castings. The work is located 



c 


c 


C 


C 


C 


C 


N 

im 
m 

N 

y 


B 


B 


B 


B 


B 

CMtlflgS 


B 


B 


B 


B 


B 


B 


B 


|L_H_>L_>L_>L_H_I 




on a machined seat. P P are the side-locatings, L L the lugs for 
the side-fastening screws, and ^the projection in which the end- 
fastening screws are located. \Yith this jig the vertical milling 



. The Wcrfc 




FIG. 421. 



FIG. 422. 



attachment was used. First the dovetailed slideway was ma- 
chined with an angular cutter, taking two cuts, one at each side ; 
then the gib- way C was machined by substituting a suitable cut- 
ter for the angular one. As all the surfaces of the castings were 
perfectly square and to size, the milling in this operation was 
done very rapidly. 



350 



TOOL-MAKING AND 



The milling of the inclined formed face D D of the castings 
was done by handling one casting at a time in the jig Figs. 421 
and 422. The amount of material removed in this operation is 
indicated by the dotted lines. A large formed milling-cutter was 
used for this work. 

Operation fourth was the drilling of all the holes in the head 
casting. This drilling was done before milling the keyway for 
the brass key, because the long central hole 7/77 had to be per- 
fectly straight and reamed to size. 

Fig. 423 is a plan partly in section of the jig. It is of the 
box type with cast legs L on four sides. The work is located by 




means of the dovetailed locator N N on a machined seat in the 
bottom of the jig, and is secured by means of a swinging strap, 
not shown, hinged at A" and fastened at Z by a thumb-screw. 
The locator N N is of machine steel, fastened to the inside of the 
jig side by two dowels C. The bushings for drilling the long 
hole are removable. They are notched at the side for the 
knurled -head locating-pins R, which prevent them from turning 
or falling out. The hole H H is drilled from both ends, half 
way from each. When reaming, the two-drill bushings are re- 
placed by others. One at the bottom fits the reamer, while the 
upper one fits the stem. In reaming this hole a shell reamer re- 
versed is used, so that the cutting-end is upward and the hole is 
reamed from the bottom. 

For milling the cross-slot or keyway, the jig shown in Fig. 
424 was used. This was made to hold a number of castings at 



INTERCHANGEABLE MA NUFA CTURING. 



351 



once. The work is located and fastened positively and with ease, 
and its removal when finished is quickly accomplished. The 
clamp shown at the front end is so made as to allow of locating 




FIG. 424. 

it quickly by means of the small latch P which is hinged in the 
clamp at K. By simply pressing back the handle of this latch 
the clamp is released and may be 
slid off. 

By reverting to Fig. 419 the 
machining required for the small 
parts will be understood. First, 
we have the back -plate V. This 
is of machine steel and is first 
milled and squared all over, the 
milling of the formed edge to co- 
incide with the formed face D D 
of the punch-head being done after 
the drilling of the four screw- 
holes. Then we have the brass 
"key." This is cut from the bar 
and cleaned up to size. The drill- 
ing of the two holes JCin the brass 
key and the four J in the back- 
plate are all done in the one drill- 
ing-jig, Fig. 425. The jig is made 
to accommodate a plate at one 
end and a brass key at the other. 
The body casting is machined so 
as to leave locating-seats for the 

FIG. 425. 

work and with a channel across 

it for the piece against which the work locates. The bush- 
ing-plate is fastened to the body by four flat-head screws. 




352 



TOOL-MAKING AND 



S S 8 S are the plate-drill bushings and T T the key-drill bush- 
ings. M M are the jig legs cast on the body. Q and R are two 
screws for fastening the work on and against the locating sur- 
faces. The work is slipped in at the ends ; then the screws are 
tightened and the holes are drilled. 

The remaining piece shown in Fig. 419 is the gib. This has 
a pin which is grooved out at one side to coincide with the taper- 
point of the gib -screw F. When the screw is tightened it forces 
the gib in and thus clamps the head in position on the perforat- 
ing-machine. This gib is of machine steel and is milled to size 
ill the miller-vise, an angular cutter being used to taper the 
edge. For drilling the hole for the pin L a simple little slip-jig 
is used. 

The tools shown possess no novel features, nor are they of in- 
tricate construction. However, they are interesting and should 
prove suggestive for other work, as they illustrate how accurate 
repetition work may be done rapidly and cheaply if some thought 
is given to the devising of simple and inexpensive tools. 

FACING AND COUNTEEBOEING LAEGE SPIDEE 
CASTINGS IN THE DEILL-PEESS. 

In a shop where paint-mixing machines are built the writer 
came across a method of facing and counterboring large castings 




J 



FIG. 426. 



in the drill-press which may prove suggestive to readers for the 
machining of other work in a like manner. An idea of the shape 
and size of the castings may be gained from Fig. 426, in which is 



INTERCHANGEABLE MANUFACTURING. 



353 



shown the nature of the work to be done. As will be seen, the 
casting has two hubs which are required to be bored to a finished 
diameter of five inches, then faced at A A, B B, C C, and D D 
respectively, and, lastly, counterbored at F F to a depth of one 
inch and a diameter of seven inches. It is at once obvious that 
the large drill-press which is equipped with a floor base is the 
proper machine for the work, and that it would be very difficult 
to do the work in any other machine. 

The boring to a finish of the cored holes in the hubs presented 
no unusual difficulties ; a large boring-bar of approved construc- 
tion being used and the projecting end allowed to run in a bush- 
ing bolted to the floor base of the drill, to which the work was 




FIG. 427. 

strapped. To accomplish the facing of the four hub faces and 
the counterboriug of the seat in an expeditious and accurate 
manner, however, required other means than those used for the 
boring. It was for this work that the special facing and 
couuterboring tool illustrated in Fig. 427 was used. 

As will be seen, the special tool consists of the regulation bar, 
turned taper at one end to fit the drill-press spindle, and rounded 
at the other to enter easily the supporting bushing on the base 
of the press. This bar has five holes let though it to accommo- 
date the boring-head. The holes are indicated in the engravings 
by letters C D E and F respectively. Three holes are for the 
cutter-bar and the other two are tapped holes for the feed-screw 
G. In the cutter-head, H is the bar, the " goose-neck" cut- 
ting-tool, a seat for which is provided in the cutter-clamps M at 
23 



354 TOOL-MAKING. 

either side of the centre as the taking of under and upper cuts 
necessitates. I is the connecting strap between the cutter-bar 
and the feed-screw, J the bar-fastening nut ; G the feed-screw 
and JTthe hand knob. JVis a cap-screw used for fastening the 
cutter and cutter-straps to the cutter-bar. 

In using this tool the bar was projected down through the 
hubs of the casting until the end ran in the supporting bushing 
at the base. The cutter-head was then in the position shown in 
Fig. 427. First the surface A was faced, the feed-screw being 
turned a little by hand at each revolution the large opening 
making this an easy matter. Next the seat F F was bored and 
finished in the same manner, feeding the spindle of the drill 
down for depth and the feed-screw of the cutting-head for diam- 
eter. After this the under face of the upper hub was faced by 
removing the cutter-head entirely; feeding the spindle down- 
ward until the upper three holes in the bar w r ere clear of the 
under face of the upper hub ; then relocating the cutter-head 
with the feed-screw in the same hole as it occupied in the first 
instance; but with the cutter-bar in the upper hole C. Thus 
the cutter-bar was merely reversed and the facing of the under 
side of the hub accomplished by feeding the spindle up instead 
of down. The two faces of the lower hub were faced in the 
same manner, the cutter-head being removed and reversed as 
required. 



CHAPTER XXIII. 

Special Machines for Accurate Work on Dies ; 
Their Use. 

PEOGEESS MADE IN THE USE OF POWEE- 
PEESSES. 

IT must be gratifying to mechanics who are interested in the 
cheap and accurate production of metal parts to note the won- 
derful progress that has been made in the use of the power-press 
during the last few years. In fact, the time has arrived when 
this modern machine has demonstrated its efficiency, when used 
in conjunction with suitable dies and fixtures, for producing 
parts of steel, iron, and other metals at a lower cost to the manu- 
facturers and to a finer degree of interchaugeability than it has< 
heretofore been possible to attain by other means. 

Where the power-press has been adopted for the production 
of metal parts, and where the full value of dies is understood 
and appreciated, the machines in Avhich they are used have be- 
come as important factors in production as any of the other 
machine tools in general use. The only reason for their non- 
adaptation in other establishments is that their use is not under- 
stood. There are a great number of shops, both large and small, 
in which duplicate small parts of standard shapes and sizes are 
being constantly made, by milling, drilling, filing, or other 
means, that could be produced at a greatly reduced cost and to a 
higher degree of accuracy by means of suitable dies in the foot- 
or power-press. In such shops, the use of the product of dies, 
that is, using sheet-metal blanks instead of castings where prac- 
ticable, would cause the people who are responsible for results in 
such shops to first open their eyes and later to double their pro- 
duction and profits. 

355 



356 



TOOL-MAKING AND 



HAND-FINISHING VS. MACHINE-FINISHING OF 

DIES. 

While numbers of special machines and devices have been 
invented for the making of all kinds of other tools, hand-work, 
to a greater or less degree, has been depended upon for the mak- 
ing of dies, from the simple blanking type to combinations of 
the tools. The advent of the vertical attachment for the univer- 
sal milling-machine helped some ; but what was wanted was a 
machine which would do the work which it was then only possi- 
ble to accomplish by the hand of a skilled mechanic with a file. 
Thus, to a certain extent, the use of dies has been prevented by 
the expense which would be incurred in the making of them. 
This excuse, however, is now ho longer operative, for there are 




i 



i 




i'.ri.r) 


' 


-ess- 




FIG. 428. 

now machines which will do the work on dies formerly only pos- 
sible by hand labor. I refer to the various die-shaping and mill- 
ing-machines which are now on the market. 

The value of these machines to all concerns in which many 
dies are made may be judged from Fig. 428, in which are shown 
a number of dies of different types which were machined and 
finished, up to the point of hardening, by the use of a die-mill- 
ing machine. Every die-maker knows the skill necessary for 
finishing such dies by hand, especially in giving the proper or 



INTERCHANGEABLE MANUFACTURING. 357 

required degree of clearance all the way through. By the use 
of machines of the type mentioned above, this can be accom- 
plished with ease ; and dies which are required to be straight, or 
tapered slightly inward, as is necessary in burnishing-dies, may 
be finished with no more trouble than would be involved in the 
finishing of a die with excess clearance. 

USE OF DIE-MILLING MACHINES. 

The die-milling machine may be used for roughing out and 
finishing, to within a thousandth of an inch or so of the templet 
lines, any kind of blanking-, trimming-, or punchiug-dies, such as 
are required to produce silverware, jewelry, bicycle parts, drop- 
forgings, typewriter parts, sewing-machine parts, etc. 

A type of die-milling machine now in use in a number of die- 
shops is so constructed that the frame of the machine is sup- 
ported on trunnions, or gudgeons, which hold it in any desired 
position, so that the operator may have the best possible light on 
the surface of the work. The spindle is perpendicular to the 
machine face and is adjustable. When arranged for milling 
blanking-dies the cutter projects through an opening in the 
chuck in which the work is clamped, and is straight or tapered 
to suit the amount of clearance required in the die. When such 
machines are used it is only necessary to drill one hole through 
the die-blank, and the cutter, starting in this hole and following 
the outline of the templet, removes the entire centre in a single 
piece. The chuck, or work-holder, on such machines is moved 
in either direction by means of two slides at right angles to each 
other and, by the use of hand-wheels on the feed-screws, the out- 
lines of the templet on the surface of the work are accurately fol- 
lowed. To assist in doing this there is a pointer at the right of 
the work which remains at a fixed position with reference to the 
cutter when the latter is below the surface of the work, and indi- 
cates its exact position. This is a convenience in cases where a 
sharp corner is to be made, when the cutter can be lowered and 
the cutting continued, guided by the pointer, thus leaving very 
little to be filed. 

Although die-milling machines are not built usually to take 



358 TOOL-MAKING AND 

very large work, they will take blanks or forgings up to ten 
inches wide by two inches thick and any length. 

DIE-SINKING ATTACHMENT. 

In connection with machines for die-making, a die-sinking at- 
tachment may be used, and if a great number of dies are required 
to be sunk, one of them is worth having. By the use of the die- 
sinking attachment, the skill and knowledge necessary to the suc- 
cessful use of small chisels, gravers, rimes, and other tools of the 
hand-die sinker, are not absolutely necessary, and a good die- 
maker will have no difficulty in doing the best work in this 
line. As these attachments can be attached to die-milling ma- 
chines in a few minutes, the machine is converted into a die- 
sinking machine. 

MACHINE FOE FILING DIES. 

In a number of shops known to the author they have also a 
special machine for filing the dies worked out in the die-milling 
machine. This machine is used for filing to a finish all kinds of 
blanking-, trimming-, punching-, and irregular or square-shaped 
drawing dies, or anything of that kind that has to be filed accu- 
rately. 

By adjusting the table of this machine to a graduated plate, 
any desired clearance from one to ten degrees can be obtained. 
By setting the machine at zero, the walls of a drawing-die, a 
burnishing-die, or an accurate trimming-die can be filed or lapped 
perfectly square, something that is impossible by hand, even by 
the most skilful die-maker. In these filing machines care must 
always be taken to have the upper end of the file supported by ad- 
justing a rest provided for that purpose. The amount of stroke 
in machines of this kind can be readily adjusted by a slot-headed 
screw in the driving-disc, carrying it further from or closer to 
the centre, as the work maj r require. For fine filing a short 
stroke is desirable. 

The samples of die work shown in Fig. 428 are only a few of 
the large variety of dies which can be finished in half the time 
and at half the expense usually required when other means are 






INTERCHANGEABLE MANUFACTURING. 



359 



used. Although it is a fact that skilful workmen .can often ac- 
complish the most astonishing results with tools which are far 
from being what they should be, an equipment of up-to-date tools 
is always to be desired in any line of mechanical work. 

A DTE-SHAPEE. 

The line drawing (Fig. 429) shows in use a device which prac- 
tically converts a milling-machine into a vertical shaper, or, as 




FIG. 429. 

usually miscalled, a slotting-machine. It is especially service- 
able in working out dies for punching-presses, following any out- 
line, regular or irregular, and giving the required clearance all 
around. As will be seen, the attachment may be used upon any 
milling -machine of the standard type, and when once fitted may 
be slipped on or off as required. 



360 TOOL-MAKING AND 

The large vertical casting seen in front clamps on to the over- 
hanging arm of the machine, and a spindle below is driven by 
a taper-shank which fits the machine spindle. Between the two 
bearings which are provided for this spindle it has secured to it 
an eccentric or cam which operates a horizontally sliding block 
which works in the cross-slot of a vertical slide carrying the cut- 
ting-tool. The vertical stroke obtained is 1J to If inches, as de- 
sired. The cutting-tool is made of ^-inch round steel, secured 
in the socket by a set-screw. This tool socket is separate from 
the vertical slide, and when the tool is set it may be turned 
around as required, so that any outline may be followed and all 
corners may be worked into. A clapper-block has been pro- 
vided which gives perfect clearance for the tool on the up-stroke. 

The drawing shows the tool at work upon a half -die of irregu- 
lar outline. This die is mounted upon a tilting-chuck which ac- 
companies the attachment and provides the necessary clearance- 
angle for die work. 

It will be noticed that the middle face between the rings is 
oblique and by turning these the pitch is thrown in the different 
directions required, a locking-pin, a clamping-screw and a bar 
for turning the rings being provided. The central post has a 
spherical head, so that it can incline as the angle requires. 

A SMALL DIE-SLOTTEE. 

The machine shown in Fig. 430 is suitable for all such work 
as small key-seating, die-slotting, both straight and taper ; also 
internal or external gear patterns where draft is required, and 
all that class of common slotting shown in Fig. 431. 

The two cross motions and the rotary table provide for fol- 
lowing any outline. 

The handle for the rotary table is arranged for using dials for 
dividing purposes, but for small divisions and rapid work it may 
be entirely removed, and the table revolved by hand, using the 
locating device, which provides twelve divisions for square, hex- 
agon, octagon, etc. 

The stroke of the machine has been fixed at 2|- inches, which 
is ample for the class of work for which the machine is intended, 
and affords greater strength than an adjustable pin. 



INTERCHANGEABLE MANUFACTURING. 



361 



The speed can be changed by means of the cone pnlley. 

The slide for the ram can be swiveled five degrees either way 
and set by a graduated index, thereby insuring the same draft 

to every part of the die. The tool- 
block is well adapted for holding spe- 
cial tools. It swivels in a centre near 
its lower end, and at the upper end, 
carried in a yoke, are two hardened 
plugs which bear on a cam that is 
bushed into the lower end of the con- 
necting rod, and from it derives a par- 





FlG. 430. 



FIG. 431. 



tially rotary motion, thus locking the tool-block on the down 
stroke and causing the tool to clear on the up strokes. 



A DIE-FILING MACHINE. 

The die-filing machine illustrated in Figs. 433, 434, and 435, 
while being designed particularly for die-making, is now in use 
in many of the best-equipped factories in this country at a variety 
of other work. 

A great deal of metal pattern work may be done on this ma- 
chine at a great saving of expense. Hardened dies, gauges, etc. , 
may be lapped much faster and truer than by hand. A variety 
of small parts too delicate to be milled may be filed accurately 
and economically. It is also well adapted to making a great 
many templets and forming- tools. 



362 



TOOL-MAKING AND 



In the following pages I illustrate a few ways in which the 
filing machine is adapted to die-making and in which it has 
proved itself a success-by actual use in various tool-rooms where 
it has been installed. 

In filing dies by hand as per Fig. 432 a man must work in a 
cramped position where the light is often very poor and where 




the lines to which he is working are generally on the side away 
from the source of light. He must watch the lines and keep his 
surface flat and true, while all the time exerting no small amount 
of strength. 

Under these conditions die -making requires a very high- 
priced man and he must spend a' good part of the time in testing 
the accuracy of the work and in resting. 

With the filing machine the work is flat on the table with the 
lines in plain view and where it will obtain the best possible light. 

The correct amount of clearance or angle is accurately ob- 
tained, and the file moving in an absolutely straight line gives 
a true, flat surface with no rounded edges. Thus the operator, 
as shown in Fig. 435, is relieved of these details and may devote 
his attention solely to guiding the work. 



INTERCHANGEABLE MANUFACTURING. 



363 



The machine does the hard work, and the operator is in a 
comfortable position and able to do more and better work. 

The cut Fig. 433 shows the machine sawing out a die. In a 
variety of dies the lines are straight or nearly so, and an ordi- 




FIG. 433. 

nary 6-, 7- or 8-inch blade may be used, sawing very close to the 
lines, giving the proper shear by tilting the table, and leaving 
very little filing to be done. 

For smaller work a narrow blade may be used which may be 
turned in small circles ; there can be had a 4-iuch blade y 3 -inch 
wide with wide kerf for this work. 

In cut Fig. 434 is shown the manner of using large files for 




FIG. 434. 

roughing. The file is clamped rigidly at both ends and the work 
held against it with the feed-screw and guided by hand. 

The file moving straight up and down gives no chance of 
rounded edges and the stock may be removed very fast. 

Fig. 435 shows the method of finishing small work with small 
files. The file is held in the lower clamp only, the upper clamp 



364 TOOL-MAKING. 

removed, leaving the work free to be taken out and examined 
at will without disturbing the file. The file clamps are made to 
take any file from the smallest up to ^-inch thick. Saws are in- 
stantly adjusted on pins on the file clamps. 

File clears on the return stroke in either direction. Clear- 
ance is provided for the file whereby it is held clear from the 
work on the return stroke. The file may be made to cut on 




FIG. 435. 

either the up or down stroke by changing the crank-pin to the 
opposite end of the crank-arm. The amount of clearance is ad- 
justable from -g 1 ^ to by means of a knurled-headed screw at the 
front of the frame. 

Tilting table. Graduated readings are provided by which the 
machine can be set at any angle with mechanical exactness. 
Files a straight and true surface. 

Feeding. A screw feed, operated by hand, is provided, by 
which the work can be fed to the file in any direction on the 
table. 

An adjustable strap is provided to hold the work down to the 
table. This is especially useful in sawing and heavy filing. 

An air-pump is provided to blow away the chips and filings, 
by which the work and file are kept clean, insuring a smooth cut. 

Four changes of speed are provided : from 60 to 450 revo- 
lutions. 



CHAPTER XXIV. 

The Art of Working Sheet Metals in Dies and 
Presses. 

USE OF SHEET METAL IN PLACE OF OTHER 
MATERIALS. 

THE marked progress that has been made in the art of sheet- 
metal working and that made in the use of the power-press for 
the cheap and accurate production of large and small, plain and 
ornamental sheet-metal parts, during the last decade, has led to 
the use of sheet metal as a material in the construction of many 
articles and appliances formerly made from other materials. 

Dies, operated by presses power, foot, hydraulic, and hand 
do a stupendous share of the work of manufacturing metal goods, 
from the small trouser button to the massive boiler head. Not 
only are these tools used for the simpler operations required in 
the cutting out of irregular shapes cheaply and accurately, but 
for bending, twisting, drawing, embossing, and forging opera- 
tions as well. 

As an instance of what is being accomplished along the line 
of sheet-metal working in dies, I may state that in the sample 
room of the great press and die works of E. W. Bliss Com- 
pany, of Brooklyn, N. Y., may be seen samples ranging all the 
way from an aluminum mandolin body to a full-size sheet-metal 
barrel, and from sheet-metal sinks and boiler heads to aluminum 
automobile bodies. 

Next to a thorough understanding and appreciation of the 
power-press as a machine tool, a practical understanding of the 
most approved methods and processes for the economic produc- 
tion of sheet-metal parts and articles in it is most necessary to 
those engaged in the working of sheet metals. Although the 
number of establishments where sheet metal is worked in dies is 
great, there are many where the most approved processes are not 

335 



366 TOOL-MAKING AND 

known, or the proper construction of the tools is not understood. 
In such works the interdiction to the rapid and accurate produc- 
tion of new and unusual shaped articles lies in those responsible 
for results not being familiar with the construction and use of 
suitable tools. 

SIMPLEST CLASS OF PEESS TOOLS. 

The simplest class of tools used in the power press are those 
for ordinary bending. In this class of punches and dies it is 
necessary to combine simplicity with durability and cheapness ; 
and one of the things to be prized is an ability to devise simple 
and effective means for producing in the fewest number of opera- 
tions the articles required, and constructing the tools so as to 
allow of being set up and operated by unskilled help. Very 
often it is possible to design a die that will accomplish in one 
operation that which usually requires two or more to produce, 
being, of course, of a more complicated and accurate construc- 
tion and requiring more skill and intelligence to operate. On 
the contrary, though, it is often preferable to increase the num- 
ber of operations by adopting simpler methods in dies that 
will stand rough usage. The nature of the work and the quan- 
tity of parts required should determine this. 

" GANG "AND "FOLLOW" DIES. 

For the production of small sheet-metal articles which are re- 
quired to be pierced, bent, formed or stamped at one or more 
points, the dies should be, t whenever possible, of the "gang" or 
"follow" types; that is, tools in which gangs of punches and 
dies are assembled and located so that results desired in the fin- 
ished blank will be accomplished progressively in one operation. 
It is only by the use of such dies that small sheet-metal articles 
can be produced in large quantities at a profit. All too fre- 
quently dies of the plain or "single " type are used, and three or 
more sets of them are required, when the same results could be 
accomplished in one operation if the proper attention were given 
to the devising of suitable tools. When sheet-metal articles are 
required in large quantities an operation saved means a great 



INTERCHANGEABLE MANUFACTURING. 367 

deal ; and if two operations can be saved even at the outlay of 
considerable money and time, the results attained will more than 
compensate for all. 

FLEECING OR PERFORATING DIES. 

The construction of punches and dies for piercing or perforat- 
ing sheet metal is comparatively simple and no very intricate 
methods are involved. Their construction is usually similar to 
that of the "gang" type, and they are used for operations 011 
work ranging all the way from ornamental thin sheet-metal arti 
cles to the punching of holes in steel beams and boiler plates. 
The holes pierced may be of any shape and spaced as desired. 
Often a number of small blanks are produced at each stroke of 
the press by dies of this class ; a sheet of metal of the required 
width being fed to the dies automatically. Perforated sheets of 
different metals are now in great demand and are used for a 
variety of purposes too numerous to mention. 

PROCESSES FOR DRAWN WORK. 

For the production of drawn and formed shells from sheet 
metal, the dies in general use consist of four distinct types. The 
first and most primitive method consists of punching out the 
blank to the desired shape and size in a plain blanking die, and 
the pushing it through the drawing die, or dies, according to the 
desired length of the shell. This manner of producing shells is 
the cheapest only where a small quantity is desired. The second 
method is by the use of compound dies and the double-acting 
press, in which the blanking punch descends and punches out 
the blank, and then remains stationary while the shell is being 
drawn and formed by the internal drawing punch. The third 
method is by means of a punch and die of the combination type, 
in which the punching and drawing dies are combined and are 
used in a single-acting press. This method is by far the most 
popular and generally used one, as well as the most practical for 
the production of plain or fancy drawn shells which are not re- 
quired to exceed one inch in height. The design and method of 
constructing dies of the combination type differ according to con- 



368 TOOL-MAKING AND 

ditions; but the fundamental principles involved are substan- 
tially the same in all of them, and may be adapted for the pro- 
duction of drawn shells of any shape which it is possible to 
produce in one operation in a single-acting press. The fourth 
and last method of drawing shells is by means of triple-acting 
drawing dies; they are used to produce shells which are required 
to be blanked, drawn, embossed, lettered, paneled, in one opera- 
tion ; and are used in triple-acting presses. 

Farther on in this work all the different types of dies used 
for the production of drawn sheet-metal work are fully illustrated 
and the most approved methods of constructing them exhaust- 
ively described. 

DEPTH WHICH MAY BE DBAWN IN SHEET METAL. 

The depth which may be drawn in sheet metal in one opera- 
tion is usually equal to about one-half the diameter for small 
cups, and one-third for large vessels. 

Where a depth greater than can be drawn in one operation is 
required, it is necessary to accomplish the job in two or more 
operations ; drawing a larger and shallower shape first, and after- 
ward reducing the shell to the desired size and shape. 

ANNEALING AND LUBBICATING IN DBA WING. 

In deep drawn work the edge becomes irregular, and requires 
trimming before finishing the piece. It is also necessary in such 
work, or in other cases where the metal is severely worked, to 
anneal the metal during the processes ; but tin-plate is ruined by 
annealing ; hence such work is drawn and annealed before plat- 
ing, or if some stiffness is required in the finished articles, one 
drawing operation may be performed after annealing and plating. 

When drawing bright steel it is necessary to use oil as a lubri- 
cant, and apply it in spots over the sheets before they are worked 
up. In working tin-plate the coating of tin, together with the 
thin film of oil left on it from tinning, are ordinarily sufficient 
lubricant ; but in drawing large pieces in a double-acting press a 
stick of paraffin wax may be passed once around the edges of the 
blanks. 



INTERCHANGEABLE MANUFACTURING. 369 

THE DBA WING AND FORMING OF DECORATED 
SHEET-METAL ABTICLES. 

By far the greatest development iu dies for the drawing of 
sheet metal has been along the line of decorated tin boxes. The 
fundamental practical points to be kept in mind when construct- 
ing dies for working such stock are as follows: Make three tem- 
plets one for the drawing die, another for the drawing punch, 
and a third for the corners, so as to get them the proper radius. 
Finish the drawing die, the punch plate, the two sides of the 
blank-holder ring and the inside of it, and the drawing die, be- 
fore starting on the cutting die or punch. Then make your trial 
draws until the proper blank is found. When the exact blank 
has been found, finish the cutting die and the outside of the 
blank-holder ring, and fit the blanking punch. Take a cut off 
the die base after the die has been hardened this base should 
be, of course, of mild steel. For decorated metal allow about 
.006-inch clearance in the drawing die; that is, finish the draw- 
ing die .006-inch and two thicknesses of metal larger than the 
drawing punch ; while for plain tin allow about .0035 -inch clear- 
ance in the drawing die. By giving this clearance there will be 
no necessity for easing up with files or scraping or grinding, and 
the designs on the metal will not be marred or scratched. Bound 
the edges of the drawing die smoothly ; if the draw is very short, 
-^ inch will be enough, and if long, increase it accordingly. Be 
careful to get all the corners of the drawing punch the same 
radius and those in the die also (plus two thicknesses of metal 
and the clearance) and lap very smooth. By keeping the fore- 
going points in mind no trouble will be encountered when con- 
structing a die of this type or in using it either. 

"FINDING" THE BLANKS FBOM WHICH TO DBAW 

SHELLS. 

The finding of the proper size blank for drawn shells is 
usually a troublesome matter ; however, the way to figure out the 
approximate size of a blank for a straight cylindrical shell is as 

follows : Take the outside diameter of the shell to be drawn and 
24 



OF THE 

UNIVERSITY 



370 TOOL-MAKING. 

add to it the length or depth of same. Then add to this ^ inch 
for every f inch of depth, and the resulting total will be very 
near the exact size of the required blank. For deep shells this 
rule will allow of finding a blank which, when the shell is drawn, 
will leave enough for trimming ; while for shallow depths, which 
will draw perfectly straight across the top, a slight reduction in 
size will be necessary. The amount to deduct will become ap- 
parent after the first trial draw. 

There are any number of rules for figuring the side of blanks, 
in which the principle upon which the finding of the diameter is 
based is that the area of a drawn shell equals the area of the 
blank from which it is drawn. But as this is never the case, be- 
cause of the fact that all metals stretch and run unevenly under 
drawing pressure, the rules work well only on paper. The way 
to construct a drawing die in the shortest possible time is to 
figure out the approximate size of the blank in the manner de- 
scribed in the foregoing ; cut out and file up a templet according 
to the result ; make the drawing portions of the die ; make the 
trial draws ; discover where there is an excess or a deficiency of 
metal ; make a new templet, which should be almost perfect, 
draw it up, and if found correct finish the cutting portions of the 
die. 



CHAPTER XXV. 

The Making and Use of Punches and Dies for Sheet- 
Metal Working. 

HAYING in the preceding chapter presented the fundamental 
principles and practical points which are necessary for the tool- 
maker to know in order to construct and use dies successfully, I 
will devote this chapter to describing and illustrating the various 
types of dies in general use. The designs have been selected as 
representing the most advanced practice in the best shops, and 
may be adopted, with slight modifications, in dies for the pro- 
duction of sheet-metal parts and articles in endless varieties. 

The number of dies shown in this chapter and the one follow- 
ing is sufficiently large, and the variety representative enough, 
to allow of the reader comprehending all types. When, in the 
case of the descriptions, it has been found expeditious to de- 
scribe means and ways for constructing, this has been done. In 
fact I have adopted this method all through the book ; for I do 
not think it is enough merely to illustrate the tool ; the mechanic 
is also interested in the manner in which it should be made and 
how the desired results may be accomplished. 

THE MAKING AND USE OF SIMPLE DIES. 

I will first sttow and describe a number of dies that are in- 
valuable for use in the average machine-shop, especially the job- 
bing tool -shop. The dies shown are the most simple and inex- 
pensive of their class for work of the kind shown. Fig. 436 is 
known best among die-makers as an emergency die that is, a 
punch and die for producing a small number of blanks of a given 
shape and size, of which the blank X is an example. 

The die A consists of a piece of -J^-inch flat tool steel, planed 
and fitted to the bolster, with the shape of the blank worked out 
at B B. In dies of this kind, when only a small quantity of 

371 



372 



TOOL-MAKING AND 



blanks are to be punched, the clearance or taper of the die from 
the cutting-edge is considerable, as the more clearance given the 
less work and skill required to finish, allowing the blank just to 
fit at the cutting-edge. This die is hardened and drawn. For 
the punch a cast-iron holder C is turned and finished and faced 
flat and smooth on the front. The punch D consists simply of 
a piece of ^-inch flat tool steel worked out and sheared through 
the die and left soft. It is then hard-soldered to the face of the 
holder C. For punching blanks from thin sheet metal to the 
number of 10, 000, this die is all right. Although some may say 





FIG. 436. 

"a botch job, " the results will be found to be all that is required. 
This style of die is used universally in almost all of the fancy 
sheet-metal goods houses, as the number of different shapes, and 
the small quantities required, necessitate the elimination of all 
unnecessary expense. 

The die shown in Fig. 437 is known as a shearing or finish- 
ing die for heavy blanks and is used for finishing work such as 
is often done in the milling-machine, or grinder. The blank Z, 
as will be seen, is a small handle punched from -g^-inch mild 
steel. In punching for heavy blanks the punch is always fitted 
very loosely to the die, and the blank produced is generally con- 
cave at the edges, and has a ragged appearance where it has cut 



INTERCHANGEABLE MANUFACTURING. 



373 



away from the rest of the stock. To remove these defects and 
marks, the blank is sheared through the finishing die, Fig. 437, 
when trimming or cutting off a shaving of stock all around, the 
blank leaves it smooth and has an appearance of having been 
milled. In making dies of this kind one of the blanks that have 
been punched is taken and filed and finished all around the edges, 
removing about .003-inch of stock all around. The blank is then 
used as a templet for finishing the die, letting it through from 
the back and filing the die straight, with just the slightest amount 




FIG. 437. 

of clearance, being sure to have the blank a good fit at the cut- 
ting-edge. The inside of the die is then finished and polished as 
smooth as possible at G and then filed taper downward from H. 
Jis the gauge plate which is worked out and finished to allow 
the rough blank to fit nicely within it. The plate is fastened to 
the face of the die by the screw J and the dowels K, so that the 
blank will rest on the face of the die I with an equal margin all 
around for trimming. Great care should be taken in adjusting 
this gauge plate to its proper position, as the small amount of 
stock to be trimmed will not allow much leeway. The die is 



374 



TOOL-MAKING AND 



hardened and drawn to a light straw color and the face is ground 
and oil-stoned, leaving it as sharp as possible. The punch is 
constructed in the regular way and fastened within the pad, as 
shown. The punch is sheared through the die and left a snug 
fit within it, after which it is highly polished and finished and 
left soft. In use, the blank Z is placed within the gauge plate J, 
and, the punch descending, it is sheared into the die at G, trim- 
ming and finishing it all around, and, if the die has been pol- 








FIG. 439. 




FIG. 438. 



FIG. 440. 



ished, leaving a nice smooth finish, producing as good a job as 
could be done more expensively in a miller. A large number of 
different small pieces in demand in the average machine-shop, 
when the quantity permits, could be finished at a greatly reduced 
expense by this means. 

When a nice polish or finish is desired on the work the blank 
is forced through a second die, which is relatively the same as the 
one shown in Fig. 437, except that it tapers slightly from the 
cutting-edge, being about .002 inch smaller at the back than at 
the cutting-edge. This die is also highly polished and finished, 
and left very hard. By being forced through the die, the metal 
around the edge is slightly compressed, and polished by the fric- 
tion. I have seen blanks treated in this manner that had all the 
appearance of having been polished or buffed. This die is 
known as a burnishing die, and is excellent for quick and cheap 
production. 

The punch and die shown in Fig. 438, although of the simplest 
design, form a great tool for accomplishing by inexpensive means 



INTERCHANGEABLE MANUFACTURING. 375 

results that generally involve considerable time and cost. The 
die shown is for finishing square holes after the first operation, 
and Y the appearance after being finished. Of course they could 
be finished by broaching, but the punch shown is the better 
method. After the holes have been blanked they are ragged and 
uneven at the edges. They are also left undersize about .003 
inch. 

The punch S is first finished on the miller to a perfect square 
of the size required that is, .003 larger than the blanked hole. 
After being polished, the face is finished dead square and the 
edges are left sharp. The punch is then hardened and slightly 
drawn. The die P is then made and worked out until the point 
of the punch can be entered, and then, using it as a broach, forc- 
ing it into and through the die, leaving it an exact duplicate of 
its shape. The die is then filed taper from the back, leaving it 
straight about -% inch from the face, as shown at P. After the 
holes for the dowel and stripper screws are let in, the die is pol- 
ished, hardened, and drawn slightly. The edges of the end of 
the punch S are then ground and rounded, so as to enter the hole 
in the stock easily. The stripper Q consists of a piece of J-inch 
flat machine steel with a channel milled down through the centre, 
in depth and width sufficient to allow the strip of steel within 
which the holes are punched to pass through it freely without 
side play. A small pin projecting above the face of the die P 
at the left side acts as a gauge for locating the holes true with 
the die. The punch and the die being set up, the strip is in- 
serted within the gauge or stripper plate Q with the first hole 
under the punch. The punch, descending and entering the hole, 
gradually compresses the metal and finishes it, leaving a dead 
^square hole with a nice smooth finish on all sides. The punch 
shown should enter the work for a full inch of its length. This 
style of die can be used for finishing a large variety of differ- 
ent shaped holes in heavy iron or mild steel, where they are 
all required to be of the same size and shape; also leaving 
a finish that it would be impractical to accomplish by other 
means. 



376 



TOOL-MAKING AND 



PUNCHING BEASS CLOCK GEAES MOVABLE STEIP- 
PING DEVICES. 

The gear shown in Fig. 441 was produced complete from 
^-inch-thick sheet brass. Holes were required to be punched at 
A, B and C, five sections D cut away, the centre hole punched, 
and the teeth cut. The gear was required to be perfectly true 
with the centre hole and to balance evenly. 

A cross-section of the punch and die is shown in Fig. 442, 
with a plan of the die in Fig. 443. Three successive operations 
produce the gear. The three holes A, B and C and the large 




FIG. 441. 

centre hole are pierced in the dies at the first stroke, the sections 
D are punched out at the second, and at the third stroke a fin- 
ished gear is cut out. Hardened and ground bushings are used 
for the dies h, d and m to allow of easy repairing. 

It is in the die X X that unusual conditions are met. This 
die, used for punching the sections D, is made in two parts, al- 
though this might not appear necessary to some. The work to 
be done, however, in this die was of such a character that satis- 
factory results would have been impossible with a solid die. 

The " spider " used in this die is shown as located and fastened 
in position in Fig. 443, and in detail in Fig. 444. As shown, 
there are five arms Z and a hole at Y. The outside of the wings 



INTERCHANGEABLE MANUFACTURING. 



377 



are turned taper, large at the back and smaller at the cutting 
face. The spider was left large all over and hardened and drawn 
to a light straw. It was then chucked and the hole T was lapped 




to the size of the hole in the gear, after which the spider was 
forced on a mandrel and ground all over to size, which was, to 




FIG. 443. 

say the least, a very nice job. The portion X X in the die plate 
was bored taper, and five shallow channels K were cut into its 
walls, as locating seats for the wings Z of the spider. 

The blanking die W, in which the gear teeth are cut and the 
finished piece is produced, was finished by reversing the usual 



378 



TOOL-MAKING ANJ) 



method ; that is, instead of shearing the punch through the die 
the die was broached by the punch. As will be seen in Fig. 442, 
this punch is finished with a stem F to fit a hole in the machine- 
steel holder E and has a hole straight through it for the pilot 
pin N. The teeth in the punch were milled and finished in the 
same manner as a gear would be, getting as smooth a finish as 




FIG. 



FIG. 445. 



possible. The punch was hardened and drawn slightly, after 
which the face was ground and stoned keen. The die W was 
then finished by using the punch as a broach. The die plate V 
was hardened and ground. Then the punch L was re-annealed 
and sheared into and through the die. Thus a perfect fit was 
attained. The punch was left soft. 

The centre piercing punch T is in one piece and is let into a 
counterbored seat J in the holder. The other three piercing 
punches for the holes A, B and C, Fig. 441, are of drill rod, and 
are located in strong supplementary holders, as shown at E, 8 
and K. 

The punch (or punches) for cutting the sections D in Fig. 
441 is shown at Q Q in Fig. 442, and a plan or face view of it in 
Fig. 445. P is the pilot pin. The punches Q form parts of the 
solid piece and were not hardened; as if they had been the 
resulting distortion would have made a fit within the die X X 
and the spider Z impossible. As it was, by shearing the sections 
Q into the die and leaving them soft, no difficulty was expe- 
rienced getting a close fit at all points. 

The only part requiring further description is the stripper, 
which is of unusual construction. As shown in Fig. 442 it is 



INTERCHANGEABLE MANUFACTURING. 379 

located on the punch, or "male" die. It comprises a flat mild- 
steel plate T, fitting around the punches proper, two blocks of 
hard-spring rubber U U, one located between the stripping^ 
plate and the punch-holder face at each end, and four studs of 
the usual construction, not shown. One of these studs is located 
at each of the four corners, with the heads let into counterbored 
holes in the back of the holder and the ends screwed into the 
stripping-plate. No other springs were required, as the rubber 
blocks answered for that purpose. 

SPEING STEIPPEES. 

Although a great many die-makers claim that spring strippers 
located 011 the punch should not be used where a stationary strip- 
per can be located on a die, still there is a large variety of work 
for the production of which a movable stripper must be used if 
accurate results are to be obtained. 

It is well known that punching or perforating dies having 
stationary strippers will distort the plates or articles punched by 
them, and often to such an extent as to require subsequent 
straightening. Thus, where accurate parts, such as are used for 
clocks, electric instruments, etc., are produced in gang dies, the 
distortion of the metal as it is worked upon by the various 
punches, will, when stationary strippers are used, prevent the 
production of satisfactory work. On the other hand, where 
movable strippers (any of the various types I mean, and not 
- merely the one shown here) are used, a clear space is left be- 
tween the punches and dies, enabling the operator to manipulate 
and observe his work quickly and accurately. The stripper 
comes down on the strip first, straightening and clamping it 
before the punches enter, while the pilot pins locate the various 
operations positively. The metal is held under pressure while 
the punching and stripping are being done, and by this means 
the work comes out perfectly straight and true. Where a num- 
ber of small perforating punches are required, they may be made, 
with the use of the movable stripper, much shorter than a station- 
ary stripper would permit. At the same time a smaller hole, in 
proportion to the thickness of the stock, may be pierced because 



380 



TOOL-MAKING AND 



of the close support which the movable stripper (when well 
fitted) gives to the punches up to the point where they enter 
the stock. 



PUNCH AND DIE FOR END FINISHING, CUTTING 

OFF AND BENDING SHEET METAL FROM THE 

STRIP WITHOUT WASTE. 

Up at the left in Fig. 446 is shown, somewhat enlarged, the 
piece made by the punch and die (Figs. 446 and 447). These 




FIG. 446. 

articles are manufactured by the million and are used as protec- 
tive seals for wooden boxes and cases, their use preventing the 
usual loss from theft while cases of goods are in transit. .They 
were produced in one operation, without waste, from Jy-inch- 
thick cold-rolled stock of the required width ; and the efficiency 



INTERCHANGEABLE MANUFACTURING. 



381 



of the die can be appreciated from the fact that it produced 
215,000 of the articles shown without grinding. 

Fig. 446 is a plan of the punch, a side view of both punch 
and die, and a plan of the die without the stripping arrange- 
ments; while Fig. 447 is an end view of the tools, with the 
stripper and the inclined fork for operating.it in position. The 




FIG. 447. 



punch consists of the usual cast-iron holder and tool-steel punch. 
The punch is finished at one end to act as the cutting-off and 
end-finishing punch, and in the centre as the bending die, the 
half-circular groove in the top being let in for the clearance for 
the stripper pin (see Fig. 447). The punch is hardened and 
drawn to a dark straw temper. 

The die consists of a flat cast-iron bolster into which the cut- 
ting-off and end-finishing die and the bending punch are located 
in dovetailed channels and fastened by flat-head screws let in 
from the bottom of the bolster. The adjustable stop plate also 



382 



TOOL-MAKING AND 



is fastened to the bolster. The stripper and gauge combined 
consists of a piece of J-inch stock with a channel cut down 
through one side wide enough to allow the stock to be fed 
through it easily, but without side play. It is fastened to the 
face of the cutting-off die by four round-head screws, as shown 
in the plan. As shown in the section of the die, the bending 
punch has a half-round groove let into the face to correspond 
with the other half in the bending-die portion of the cutting-off 
punch. The cutting-off die and the bending punch are hardened 
and drawn to a light straw, after which the sides of the bending 
punch are eased off a bit toward the bottom, so that the metal, 
when bent, will cling to it instead of to the bending portion of 
the cutting-off punch. 

The stripping arrangements, as shown in Fig. 447, consists of 
the following parts : The stripper proper is a round stud let into 
a small casting located in the dovetailed channel for the bending 
punch in the bolster. This stud has a pin let through the back 
end to prevent it from springing out too far, when the punch is 
up, by the action of the spring at the back. A stronger pin is 
let through the enlarged portion or collar of the stud, so that the 
inclined fork, which is fastened to the back of the punch-holder, 
will, while descending, move the stripping-stud back and off the 
face of the bending punch. 

When the die is in use, a strip of metal is entered beneath the 
gauge plate and is allowed to project a slight distance beyond the 




FIG. 448. 



cutting die. The press is stepped and the end of the stock is 
trimmed and finished to the shape shown in the plan of the die. 
The stock is then moved forward against the stop, and, as the 
punch descends, the piece is cut off and bent over the bending 



INTERCHANGEABLE MANUFACTURING. 383 

punch, the cutting punch descending about f inch below the cut- 
ting-edge of the die. As the punch ascends, the inclined fork 
releases the stripping-stud which springs outward and throws the 
finished piece off the bending punch and into a box at the front 
of the press. The parts are thus produced without waste and as 
rapidly as the stock can be fed. At first strips of metal were 
used in the die, but after a short time rolls of the required width 
with 200 feet of stock in each were used. They were placed on 
a reel at the left of the press and the stock was fed automatic- 
ally, through a pair of straightening rolls. 

TWO DIES FOE METAL BOX-COEKEE FASTEXEES. 

The article shown in Fig. 448 is a sheet-metal trunk corner. 
These corners are made flat, and are intended to be bent at right 
angles after one end is nailed on to the trunk. The notches on 
the sides serve as guides for nailing the corner in the proper 
position, and they also facilitate the bending. The corner is so 
made that the edges bind the wood closely when nailed on, thus 
making a very rigid corner. 

Two operations are necessary. The first, that of notching and 
cutting off the blanks, is done by the punch and die shown in 
Fig. 449, showing a section of the punch and die and a plan of 
the die. There are three punches fastened in a machine-steel pad, 
which is in turn fastened to the face of the holder by six flat-head 
screws. The end-notching and cutting-off punch is at the right, 
and is about ^ inch shorter than the centre notching punch at 
the left. This is so that the centre notching will have been ac- 
complished before the blank is cut off. 

The die is made in the regular way, with two short gauge 
plates at the right end, and with the stripper extending entirely 
across the face of the die. When the blank is cut off it drops 
off at the back, as the press is inclined and there is no gauge 
plate to hinder it. 

For the finishing operation that of drawing and forming the 
six raised spots and perforating them in the centre the punch 
and die, Fig. 450, are used. The punch is in a dovetailed 
channel in the holder and fastened to the bolster by two flat 



384 



TOOL-MAKING AND 



screws let in through the bottom. The dies proper are six tool- 
steel bushings, finished on the face with a forming tool to the 
shape required, and a small hole let down through the centre. 
They are hardened and forced into counterbored holes in the die 
plate. The die plate is beveled at the edges to correspond with 




I Stop 



D O/ 



i O 



FIG. 449. 

the punch at F F. The die plate is left soft and the punch is 
hardened. The drawing-punch sections are at E E E E, and are 
finished as shown in the face of the punch. The gauges for 
locating the work upon the die are three in number, and are 
located as shown at G G G. The press in which the tools are 
used is inclined and the blank is placed on the die with two 
sides against the gauges G G G. After the punch has de- 
scended and returned, the finished work remains sticking to 
the die, from which it is thrown off by the operator by his en- 



INTERCHANGEABLE MANUFACTURING. 



385 



tering a thin fork under the front right-hand end and snapping 
the piece off. 

Both the dies shown and described herein were used in a sheet- 




c 



Fifi. 450. 

metal establishment in which rapid and economic production is 
absolutely necessary in order for their products to sell at a profit. 

PIEECIXG AND SPEEADING DIE FOE BOX STEAPS. 

At Fig. 451 is the outline of a portion of sheet-metal box 
strap used for binding the edges of wooden boxes. These straps 
are produced in coils of from 5, 000 to 6, 000 feet, with slots 



FIG. 451. 



pierced 2 inches apart along the entire length. These slots are 
first punched and then spread to make openings for the nails. 

The spreading of the slots makes the opening large enough for 
25 



386 



TOOL-MAKING AND 



the nails and does away with the liability of the strap breaking 
out at the eyes when the nails are driven into the wood. The 
material is -% inch wide and 0.032 inch thick. 

The punch and die used to produce these straps are shown in 
Figs. 452, 453, with a plan view of the punch above in Fig. 452. 




FIG. 452. 



These tools show how very frail punches may be used. The 
capacity of this die is 30,000 feet of stock a day, fed automatic- 
ally. 

The punch consists of the stem of cast iron ; the two punch - 
holders C C of machine steel; the clamping plates G G of the 
same ; the piercing punch B and the spreading punch A ; eight 
screws for fastening the clamping plates and two cap screws for 
fastening the holders to the stem. The punch -holders are located 
in square milled channels F F in the face of the stem, and are 
fastened in position by the screws D. The punches are of uni- 
form section and double ended, and are* located in seats in the 
holders and clamping plates. The faces are sheared so that two 
points will enter the stock first and thus the holes will be pierced 
progressively. The spreading punch A is bevelled and rounded 
at the face, so as to spread the stock gradually. These punches 



INTERCHANGEABLE MANUFACTURING. 



387 



are hardened in oil between flat plates and are drawn to a blue. 
They last a very long time, as they can be used from either end 
and ground until only a short section remains in the holder. By 
shearing the cutting faces of the piercing punch the clamping lid 
G holds it tightly ; it is surprising how easily the stock is pierced. 
The construction of the die is of a rather novel character, and 
after numerous experiments it was found to be the best. It con- 
sists of the usual cast-iron bolster, with two dovetailed channels 
let into the face for the dies, the dies H H and 1 1, screws for 




FIG. 453. 

locating, adjusting, and fastening them, the stripper and gauges, 
which are combined in one plate, and the screws and dowels for 
locating and fastening it to the face of the bolster. 

The piercing dies fit tightly in the dovetailed channel at the 
right. They have slots as clearance for the fastening screws and 
to allow of adjustment. Pieces of T 5 7 -inch flat steel at each end 
of the channel serve as brackets for the adjusting set -screws 
K K. This way of making the piercing die allows of the faces 
being ground when dull with very little trouble, and insures its 
long life. The spreading die is in one piece and is fastened and 
located within the channel J by the two flat-head screws. In the 
true sense of the word it is not a die, but instead a support for 
the spreading punch A. The stripper and gauges, in one piece, 
are machined from a piece of f -inch-thick machine steel, with a 
narrow channel milled down along one side as a gauge for the 
stock, and widened at the left-hand end as clearance for the stock 



388 



TOOT^-MAKING AND 



after the pierced hole has been spread. The hole in the stripper 
for the punches is a tight fit, this being necessary because of the 
frailness of the punches; the stripper is heavy for the same 
reason, as, in order to accomplish good results and to insure the 
longevity of the punches, they must never entirely leave the 
stripper. 

When in use the metal is fed from a reel at the right and 
wound up again on a reel at the left, the press running contin- 
uously for two hours without any attendance. There is a large 
variety of pierced work which could be produced at the minimum 
of cost by dies of this construction. 

AN IMPROVED PIERCING DIE. 

Fig. 454 shows an improved piercing die, used in the same 
establishments for piercing holes in 100 -foot lengths of flat cold- 
rolled stock, I inch wide by ^ inch thick, feeding the stock 




FIG. 454. 

automatically as described for the first die. The holes pierced 
were No. 24 gauge, 5-J- inches apart. 

The punch pad has holes bored and threaded for the two 
punch-holders. These holders are turned from 1^-inch round 
stock, with holes for the Stub -steel punches. They are flat milled 
on two sides for a wrench. The backs of the punches are enlarged 
and tapped for the adjusting or butt screws Jtf M. When the 
punches became short through grinding, a piece of the same 



INTERCHANGEABLE MANUFACTURING. 



389 



stock is placed between them and the faces of the butt screws. 
The punches are fastened by the set screws N N and the semi- 
circular faced plugs 0, thus doing away with the notching or 
flattening of one side of the punches and allowing of using them 
for a greater portion of their length. 

The die is composed of the bolster, the two piercing dies, 
lapped and ground to size and forced into counterbored holes in 
the face of the bolster; the stripping plate and gauges, all in 
one ; the two punch bushings P P lapped to a tight fit for the 
punches, and the screws Q Q and dowels R R for fastening and 
locating the stripper plate to the face of the bolster, as shown. 



GANG DIE FOR BOX-LID FASTENING PLATES. 

The engraving (Fig. 455) shows a fastening plate used for 
hasps for fruit crates and box lids, and Figs. 456, 457 show the 




FIG. 455. 



punch and die for its production. The article has three holes 
pierced in it, a portion of the centre drawn and formed, and the 




FIG. 456. 

ends trimmed to a curve. The stock used was cold-rolled sheet 
metal, and the punch and die were of the "gang " type. 

In the punch A is the stem or bolster, I the punch pad, B B 
the two small piercing punches, C the large piercing punch, D 
the drawing and forming punch, E the trimming and cutting-off 



390 



TOOL-MAKING AND 



punch, which trims and cuts off at F and G respectively, and If 
the six flat-head screws for fastening the punch pad to the holder. 

In the die J J are the small piercing dies, K the large one, L 
the drawing and forming die, M and N the cutting off and trim- 
ming die, and the remaining parts the stripper and gauge plate. 
The die plate was hardened and drawn to a light straw. The 
punches, except the forming and drawing punch, were hardened 
and drawn to a dark blue, the drawing punch was hardened and 
drawn from the back, getting tne back soft and leaving the draw- 
ing face very hard. 

The stock is fed to the die from left to right automatically, 
the holes being pierced first, then the formed and raised portion 




Stripper PUU 

IP 




FIG. 457. 

drawn, and, lastly, the finished plate cut off and the front end of 
the next piece trimmed. The drawing punch is left the short- 
est; this being done so that the piercing punches will have 
pierced the stock and the finished piece have been cut off before 
the raised portion of the next piece is produced ; thus there is no 
shifting of the metal while the different operations are being ac- 
complished. The metal used for the fasteners came in rolls of 
the required width. It is straightened somewhat by the rollers 
of the automatic feed and flattened by the flat portion of the 
drawing punch. 



INTERCHANGEABLE MANUFACTURING. 391 



LAEGE DEAWI^G DIES FOE CIECULAE SHELLS. 

The Figs. 458 and 459 show a collection of large drawing and 
re -drawing dies for producing from flat blanks large circular 
shells. These dies were made in the works of the E. W. Bliss 
Company/ and formed part of an order of presses and dies for a 
sheet-metal-goods concern in Europe. They were made to metri- 
cal dimensions, the diameters ranging from 290 to 600 millime- 
tres or, say, from 11.4 to 23.6 inches, the largest set at the left 
and the smallest at the right. Each set consists of a drawing 
punch, a drawing die, and a blank-holder. Drawing dies of this 
type differ from those used for small work in that they draw the 
articles from blanks previously cut, instead of being provided 
with cutting-edges which punch the blank at the same stroke. 
The outer edges of the drawing dies are turned to the same 
diameter as the blank to be drawn, and the operator locates the 
blank by simply laying it on the face of the die and locating the 
edges with his fingers. Very often, however, shells of different 
heights are produced in the one die. This of course requires 
blanks of different sizes and gauge plates to locate them true on 
the die. Dies of this type are made to produce large shells of 




FIG. 458. 



any style or shape, and draw the article at one or more opera- 
tions, according to the shape and depth to be obtained. In work 
of considerable taper, such as large flared pans of thin stock, two 
or more blanks may be drawn at the same stroke of the press. 



392 



TOOL-MAKING AND 



Fig. 458 shows seven sets of drawing dies with inside blank- 
holders. As shown here, they are used for re -drawing shells 
which have been first drawn in dies having outside blank-holders, 




like the dies shown in Fig. 459. The inside blank-holder holds 
the partly finished articles at its lower bevelled edges between 




Cutting Puneft'and Blank Holder 




FIG. 460. 



the bevelled edge of the punch and the bevelled seat in the die, 

while the punch draws it into a deeper shape of reduced diameter. 

These drawing and re-drawing dies are mostly made of a spe- 



INTERCHANGEABLE MANUFACTURING. 



393 



cial grade of cast iron, treated in such a manner as to give a very 
dense and uniform texture to the metal at the working surfaces. 
To do very accurate work, however, steel rings are set into the 
dies, and the blank-holders are made of steel castings, which adds 
considerably to the durability of the tools. For shells which 
have to be finished to very accurate diameters hard steel "siz- 
ing " punches and dies should be used after the last re-drawing 
operation. 

THE DRAWING OF DEEP SHELLS FROM SHEET 

METAL. 

The manufacture of deep sheet-metal shells, of small diameter, 
has progressed constantly, and to-day results are attained which 
a few years ago were only thought of as remote possibilities. 



Jn< Sir' HIGH 4-t-' DIAMETER 



pi 9 '/ // 

Ifk 37S-HIQH 4 [ 




S-DIAM. 



y HIGH 3^- DIAM. 



8 HIGH 2|- DIAM. 



1 Q|-' HIGH 2f- DIAM. 



< 13 HIGH 24- DIAM. 

16" HIGH 2" DIAM. 



FIG. 461. 



The operation of drawing sheet-metal shells has really changed 
but little ; the same means, with slight modifications, being used 
at the present time for the production of deep shells of small 
diameters which formerly were thought practical only for pro- 
ducing shells of shallow depths and large diameters. The 
presses, in which drawing dies are used, have been built larger 



394 



TOOL-MAKING AND 



and stronger, and with a greatly increased length of stroke, 
while the dies have been simply modified for a wider range of 
work. 

As an illustration of what is being accomplished in the draw- 
ing of sheet metal we show in Fig. 461 the successive results of 
the eight operations required to draw a shell copper -J-g- inch 
thick, 16 inches deep by 2 inches in diameter. Two of the shells 
are assembled and shown at the bottom. They are used as parts 
of a patented mineral -water cooling apparatus. 

The blank required for this shell was 8 inches in diameter, 
and the thickness of the stock decreased from T ^ at the start to 
-fa at the finish. The die used for the cutting and first drawing 



r 




Pundx Holder 



Shtfl Product to Ftart 




FIG. 463. 

operation is shown in Fig. 460, and is of the double-acting type. 
In the punch the cutting and blank-holder part is a forging of 
wrought iron with a tool -steel ring welded on as shown for the 
cutting portion. The projection B is for locating it true on the 
outer slide of the press. A is the drawing punch, the stem of 



INTERCHANGEABLE MANUFACTURING. 



395 



which is reduced as shown to fit the inner slide or ram of the 
press. 

In the die, D is the cutting-edge, where the blank is cut ; E 
the face upon which it is held by the punch while being drawn, 
.Fthe drawing die, and G the 
knock-out pad. This die is set 
up in the press and the metal 
is fed to it and blanked and 
drawn to the shape shown in 
the first operation in Fig. 465. 
The press has a toggle move- 
ment which insures a more per- 
fect " dwell" of the blank- 
holder slide than could be 
maintained in a cam drawing 
press, and effects a large saving 
in friction and power. The ad- 
justment of the drawing-punch 
plunger is effected by means of 
a double-ratchet device, which 
is handy and quick of opera- 
tion. 

For the seven re- drawing 
operations in the production of 
the shells, dies of the type 
shown in Fig. 462 were used. 
These dies were of the push- 
through type and were used 
without the usual inside blank- 
holders, as the small difference 
in the diameter of the redrawn 
shells did not require it. In- 
stead of the shell being pushed 
completely through these dies, 
they were fed to the top of 
the die by an automatic knock-out on the press in which they 
were used. 

By noting the difference in the diameters of the re-drawing- 



Blank, 8 inches diameter. 
FIG. 463. 



396 



TOOL-MAKING AND 



operations, Fig. 463, the manner in which a shell of small 
diameter and great height may be drawn and the number of 
operations required will be understood. The lubricant used in 
the re-drawing operation was lard oil, and there was a decided 
polish on all the shells produced. The dies used for the re-draw- 
ing operations were made from a special grade of chilled iron, 
while the punches were of tool steel. Both punch and die for 
each operation were highly polished. The die and punch used 
for the sizing or finishing operation were of tool steel, and were 
hardened, ground, and lapped to the required size. As will be 
seen, the drawing of deep tubes of small diameters is not such a 
difficult accomplishment as some people imagine ; all that is nec- 
essary being the adoption of proper dies, their accurate construc- 




FIG. 464. 

tion, and their use in presses which have been built specially for 
such work. When the difference in the diameters of the re-draw- 
ing operations exceeds \ inch, inside blank-holders must be used. 
For certain metals inside blank-holders, in the re -drawing dies, 
will allow of the desired results being accomplished in three or 
four operations (through the perfect holding of the metal while 
drawing or re -drawling), which would require six, seven, or more 
operations were dies adopted in which inside blank-holders were 
not used. 

Fig. 464 shows the tools used. The punches are reduced at 
the end and threaded to screw into the holder in the press ram. 
The dies are shown beneath and punches, and the locating seats 
in each are shown plainly. The devices shown at the bottom 
comprise the knock-outs and other tools. 



INTERCHANGEABLE MANUFACTURING. 



397 



HOLLOW CUTTERS FOE PUNCHING LEATHER, 
CLOTH, AND PAPER. 

When work is to be punched from leather, cloth, or paper, 
hollow cutters cr "dinking dies," will be found to give better 
satisfaction than the punch and die of the usual construction, as 

they are cheaper to make, and there 
is practically no limit to the number 
of pieces that can be cut at one stroke 
of the die, which may be operated in 
the ordinary press, or by hand with 
the use of the mallet. 

The die is made from stock rolled 
specially for this class of work, and is 
usually composed of Swedish iron, 

FIG. 465. , . n 

laid up with a good grade of tool 

steel, as shown in cross-section in Fig. 465, the steel being 
laid on the straight side of the bar, and a 20 -degree bevel 






FIG. 466 a. FIG. 466 b. 

edge given to what is to be the outside of the die. A templet 
is made of sheet metal of the exact shape of the work 





FIG. 467. 



FIG. 468. 



wanted, and this is used by the smith in welding up the blanks. 
The accuracy with which forging is done with these. dies is re- 
markable, a variation of -^ inch from the pattern being the 
exception rather than the rule. The cutter, after being welded, 
is taken to the vise and worked out on the inside with the file to 
the exact shape of the templet ; allowance having been made on 



398 TOOL-MAKING. 

it for the slight amount of shrinkage caused by the hardening. 
The die is then finished on the outside by grinding. 

When the tool is to be used in a press a handle will not be 
necessary ; intended to be used by hand, a handle is secured to 
the upper part of the die. This handle is forged with a project- 
ing lip shutting over on the outside of the cutter, the weight of 





FIG. 469. 

the blow being taken by this shoulder which bears directly on 
the upper part of the cutter. This is secured in place by rivets, 
and is then taken to the fire and brazed in the usual manner, 
using borax as a flux and soft brass solder for the brazing. This 
operation is generally done after the die is ground, and before it 
is tempered. 

Sometimes the die is used in an inverted position, being laid 
on the press with the cutting-edge up, the work being placed on 
the same, and as the gate of the press descends the 
material is forced through the die. When this method 
is practised, the die should be brazed to a foundation 
FIG. 470. plate, in order that it may be properly secured to 
the press. The handle or this foundation plate may 
be removed, and the die may be repaired or worked over into 
other shapes if required. 

For a surface to be used for the cutting-edge of the die to 
strike upon, there is nothing better than a built-up block of hard, 
seasoned rock maple, set endwise of the grain. This is made by 
sawing up a plank into pieces about 4 or 6 inches long, gluing 
them up into a block, and then securing it by bolt passing 
through the whole, as shown in Fig. 469. This will be found to 
give better results, with less wear, if kept damp ; that is, a wet 
cloth should be laid on the block when the same is left at night. 
The group of cutters shown in Figs. 465-470 illustrate several 
of the many styles of "dinking dies" which are in general use. 



CHAPTER XXVI. 

The Making and Use of Punches and Dies for 
Sheet-Metal Working. Continued. 

A PUNCHING AND CURLING JOB. 

IN Fig. 471 are shown the results of successive operations in 
the production of a sheet-metal part of unusual shape which 
formed part of a patented apparatus. 

The upper diagram in Fig. 471 shows the results of the first 
and second operations. The holes in the ends were punched, the 




FIG. 471. 

ends were shaped, cutting off the piece, and twenty-nine slots 
along one side were punched. 

The piercing of the holes, shaping the ends, and cutting off 
the pieces were done in the first operation by the punch and die 
shown in Fig. 472. The work in this operation is all at the ends, 
necessitating a punch and die of different construction from those 
usually used. In the die section the die for piercing and that 
for cutting off and end-shaping are dovetailed into the face of 
the cast-iron bolster, one at each end, and secured by taper dowel- 
pins. The gauge-plate extends along the entire length of the 
bolster, and is fastened to the die faces with the stripper plates 
by flat -head screws. The stripper plates are made of extra heavy 
stock and are worked out so that the punches are supported while 
doing their work. In the punch section the construction is 
similar to that followed in the die section, in that the cutting- 



400 



TOOL-MAKING AND 



off arid end-finishing punch is dovetailed into the holder and 
located by means of a taper dowel ; while the piercing punches 
are let into a pad, dovetailed into the holder, and located in the 
same manner as the cutting-off punch. The piercing punches 




Cutting Off and 
Dowcl PLAN \ ,' Ead-FinJshintr- 







FIG. 472. 

were made of drill rod, hardened, tempered, and of a length 
sufficient to allow of their always being in the stripper, thus ob- 
viating the tendency to bend or snap off. The stock, which re- 
quired no side trimming, was fed across the die faces automatic- 
ally. The four holes were pierced at the left, and then the last 




FIG. 473. 

end of the piece and the first end of the next piece shaped, and 
the piece was cut off by the large punch at the right. 

For the second operation, that of piercing the twenty-nine 
slots, a punch and die of intricate and accurate construction 
were required. In Fig. 473 are shown a front elevation partly 



INTERCHANGEABLE MANUFACTURING. 401 

in section, and a vertical cross section, respectively. I illustrate 
only the pnnch, as the die was almost identical in construction. 
The punch section consists of, first, a cast-iron holder (7, then a 
supplementary punch-holder A, the latter in two sections, the 
twenty-nine punches D, and a spring- actuated stripper H. The 
spring stripper is left off the plan so that the construction of 
the other parts may be more clearly understood. The manner 
in which the punches are located and fastened is unusual. First 
two pieces A of ^-inch-thick annealed tool steel were planed to 
butt together sidewise and then dovetailed into C. These two 
sections were then clamped together, and twenty-nine slots were 
milled into them, in depth equal to half the width of the pierc- 
ing punches. The manner in which the punches were let into 
these slots and upset at the back, the two sections strengthened 
by dowels B B, and then driven into the dovetailed channel in 
the holder, will be understood, as well as that the milling of the 
slots in the sections A A of the pad was an accurate job. It was 
accomplished by careful work on the universal milller. The 
slots were milled about . 002 inch smaller than the thickness of 
the punches. The making of the twenty-nine punches was also 
a job requiring skill and care. The punches were left over size 
all over, then hardened between oiled plates and drawn to a dark 
straw to within -inch of the backs, and from there on to a 
dark blue to allow of upsetting them within the pads at the 
backs. They were then ground "on all sides to size. 

The spring stripper plate H H was worked out to fit around 
the punches rather snugly, so as to give them as much support 
as possible up to the point w T here they entered the stock. The 
faces of the punches were sheared so as to commence to cut at 
both edges before the centre of the stock was cut away. This is 
shown in the end view at I. 

The die was made in the same way as the pad A A, being in 
two sections, which were located together by dowels, and were 
dovetailed into a bolster of the usual kind. Considerable care 
was required in the hardening of the die section, and in the grind- 
ing of the faces afterwards, in order to insure the alignment be- 
tween the twenty-nine piercing dies and the punches ; and al- 
though the man who hardened them understood his business and 
26 



402 



TOOL-MAKING AND 



turned out a good job, it was necessary to peen the edges of some 
of the pad slots so as to crowd a few of the punches over a thou- 
sandth of an inch or so. It was not found necessary to grind all 
of the dies, although about every third one had to be touched up 
on the sides with a fine wheel, taking care just to touch the tight 
spots. 

When using the punch and die a blank was located against 
stops on the face of the die and the press was "stepped." As 

the punch descended the spring 
stripper plate H H flattened the 
stock and held it securely in posi- 
tion while the slots were being 
punched. As the punch rose, the 
stripper forced the work from the 
punches and allowed it to drop off 
the die face. After the punch 
and die had been in use a short 
time it was found necessary to 
re -grind the die faces, as some 
of them had sheared. Then the 
punches were entered into the dies 
and solder was run around them 
at the pad faces. This rendered 
the alignment perfect, and we 
had no more trouble. 

It will be seen in Fig. 471 
that the sections left between the 
slots punched in the second ope- 
ration have to be curled alter- 
nately, half of them one way and 
the other half the other way. 
It was at first thought that a die 
of considerable intricacy would be necessary ; but it was at last 
decided to do the curling in two operations but with one die, 
and that a quite simple one. 

I show in Fig. 474 a vertical cross-section of the curling die. 
L is the punch-holder; TTthe curling punch, located in a square 
channel in the holder face and fastened by three flat-head screws ; 




FIG. 474. 



INTERCHANGEABLE MANUFACTURING. 



403 



N N are the portions that do the curling, while the cutaway sec- 
tions E are clearance channels for the sections of the stock which 
have to be curled in the opposite direction. P is the work, Q a 
spring supporting pad with the face worked out at to the 
radius of the curl; U is a gauge-plate for locating the work 
against the pad Q ; R is the bolster ; 8 the channel in which the 
spring supporting pad moves, and T one of three spring studs. 
The work is placed between the gauge U and the pad Q and 
against a gauge at the end. As the punch descends, half of the 
sections to be curled, or every other one, enter the curling 
grooves N, while the others enter the clearance channels W. 
The punch continues to descend and the metal follows around 
the curling grooves until the curls are completed, the pad Q 
descending with the punch. As the punch rises, the pad Q rises 
also and carries the work out of the locating slot between the 
pad and the gauge, and as the punch rises higher it leaves the 
work free on the top of the pad Q from which it is removed by 
hand. The fourth operation, curling the remaining sections in 
the opposite direction, is accomplished in precisely the same 
manner. 

DIES FOE SHEET-METAL BAG-CLASPS. 

In Fig. 475 are shown three views of a patented sheet-metal 
bag-clasp which was produced entirely by the use of dies, there 




FIG. 475. 



being no hand work, except in feeding. The dies here shown 
are the most interesting ones of the set employed. 

The clasp consists of eight parts: the embossed front A, a 



404 



TOOL-MAKING AND 



thin tin pad B fitting into the embossed part at the back, the 
hook or clasp part C, the spring D, the lever E, the two straps F 
in which it is located, and two rivets G for fastening the spring 
D to the hook C. 

The first part produced was the embossed front A. This was 
struck up and drawn from very thin, soft sheet-brass blanks, 




FIG. 476. 




which had been previously cut, the result being shown in Fig. 476. 
The second operation on the embossed piece was punching out the 
drawn and embossed portion from the rest of the blank, leaving 
the scrap as at Fig. 477. The piece produced has four small 
wings, which are afterward bent upward in a simple die in the 




r 



foot-press and then bent inward, enclosing the pad within the 
embossed part. The die for the trimming and blanking opera- 
tion is shown in Fig. 478. The punch has a spring stripper, 
while the face of the die is open and clear; thus the locating of 
the work is rapid, the work being pushed through the die and 
the spring stripper stripping the scrap from the punch when it 
slides off, the press being tilted. 



INTERCHANGEABLE MANUFACTURING. 



405 



In Fig. 479 we have the punch and die used to produce the 
pad shown at the top of the cut. The work consists of cutting 
and bending up the four wings G and punching out the blank to 
the shape shown. The tools used for producing this part were 
of the combination blanking, piercing, and bending type, com- 
pleting the work at one stroke of the press. In the die N is the 
bolster, the blanking die, Q the piercing and bending punch 




FIG. 479. 

pad, R R two of the piercing and bending punches, P the spring 
stripper in the die, 8 the spring, T T the two gauge plates be- 
tween which the stock is fed, and U the stripper for the stock. 
In the punch H is the holder, J the blanking-punch, K K two of 
the piercing and bending dies, I the punch pad, and L the punch 



406 



TOOL-MAKING AND 



stripper. The press was tilted backward, the stock was fed from 
front Jto back, and the finished piece, after being stripped from 
the punch, dropped off into a box. 

In Fig. 480 we have the clamp portion before the bending 
operation. In the production of this part four operations were 



a* 




[JAA 



FIG. 480. 



necessary. The first was the punching out of the plain blank. 
This was done in a simple blanking die. The second and third 




EE 



cm a 




E E 





l_l__Mljilia _ t , "'[JlJi-iJ ~*, 9 , ' l-J' 11 ""-, . x< ., ,, fli'i'ii-' 

rW [tr*! M t"! tefl 1 1 & F F ,^ 



Front of Die. 
FIG. 481. 



operations were both done in one combination die. The tools 
are shown in Figs. 481, 482, and 483. The work to be done by 



INTERCHANGEABLE MANUFACTURING. 



407 



these tools is the piercing of the eight slots X, Fig. 480, the pierc- 
ing of the two holes W, the drawing of four shallow seats for 
locating the straps shown at F in Fig. 475, the throwing up of 
three small projections Y, and, lastly, the bending of part Vto 
the shape shown by the dotted lines in the edge view, Fig. 480. 

In the dies, Fig. 481, E E is the section where all the pierc- 
ing is done, and F F the section where the forming, drawing, and 




Plan of Punch. 

FIG. 482. 



bending are done. As shown, the two sections are locked 
together at 2 2. The bolster used with the dies is not shown. 
However, the dies were located in a channel and held and fast- 
ened in position by set-screws at each end of the channel. In 
die E E, where the piercing is done, 5, 3 and 4 are the piercing 
dies, 6 6 the two gauges which locate the blank for piercing, and 
7 the stripper. The gauge-plates and stripper are located and 
fastened by the dowel-pins 9 and the two flat-head screws 8. In 
the section F F, where the drawing, forming, and bending are 
done, 10 10 are the seat drawing dies, 11 is where the small pro- 
jections are formed, and 12 where- the neck V of the work is 
bent ; 13 13 are the two gauge-plates between which the work is 
located, while 14 are the stripping edges. 

The punch -holder, Figs. 482 and 483, is of the usual construc- 
tion, while the method of locating and fastening the punches is 
somewhat different from that usually followed. The drawing, 



408 



TOOL-MAKING AND 



forming, and bending punches are all contained in one steel 
block, which is worked out on the face to match the dies in F F. 
This block is dovetailed into the holder, and is then fastened 
and located in alignment with the dies by the set-screws shown 
at the side. 

The section of the punch-holder devoted to the piercing opera- 
tion is built in the usual manner ; that is, a machine-steel pad, 




FIG. 483. 

in which all of the piercing punches are located, is fastened to the 
face of the holder at this side by four flat-head screws. 

The piercing punches were rather slender and frail, and it 
was necessary to be very careful in locating them in the pad. 
This was accurately accomplished by working out the pad and 
the piercing dies at the same time. Then the punches were fin- 
ished to fit the dies, hardened and drawn, and then forced into 
the pad, upset at the back, and hard solder run around them at 
the face of the pad. As the holes for them in the stripper were 
made good fits, and as the stripper was of considerable thick- 
ness, all danger of bending, twisting, or breaking was obviated, 
as the punches never left the stripper. 

The dies E E and F F were hardened and drawn a very little. 
The punch block, in which the drawing, forming, and bending 
dies were contained, was hardened on the face and left hard. 
All of the slot-piercing punches were hardened between oiled 
plates, while the two-hole piercing punches were hardened in oil. 

Referring to Fig. 475 we have the flat spring part D of the 
clasp to complete the article. It is necessary to round off one 
end of this, punch teeth in the other end, punch two small holes, 
throw up a small lug, and bend and form the metal to a given 



INTERCHANGEABLE MANUFACTURING. 409 



shape. All of the work on this spring was done in the fol- 
low-die shown in Fig. 484. The stock, coming to the proper 
width, was fed between the gauge-plates on the die and against 
the stop-pin by an automatic roll feed, and then, the punch de- 
scending, the holes were pierced and the front end was trimmed. 




Stop 



Forming^ 




Str 



FIG. 484. 

At the next stroke the teeth were punched in, the piece was cut 
off, bent, and formed, and projection was thrown up, the front 
end of the next piece was trimmed and the two holes were 
pierced. This die was an exceptionally rapid producer, an in- 
clined press being used and the finished parts falling off at the 
back. 

For producing the straps in which the lever worked a die 
which produced three at once was used for blanking, while the 
bending was done in a simple little push-through die in the foot- 
press. The lever was cast. In assembling the various parts to 
form the complete article shown in Fig. 475 a few foot-press dies 
of very simple construction -were used. 



410 



TOOL-MAKING AND 



A TRIPLE-ACTION DIE FOR BLANKING, DRAWING, 

AND EMBOSSING AN ALUMINUM SHELL AT 

ONE OPERATION. 

As as instance of what is being accomplished at one opera- 
tion in the line of embossed shells, I show in Fig. 485 two views 
of a shell which formed the cover of a box for a toilet prepara- 
tion, and for which an order for 
almost one million was secured. 
The material used was sheet alu- 
minum of a special alloy, and the 
result in the finished shell was very 
pretty. 

A triple-action " Bliss " cutting, 
drawing, and embossing press and 
a triple- action die were used. The 
chief advantage to be gained by 
the use of triple -action dies lies in 
the fact that the finished work from 
them is delivered below the die in- 
stead of at the top, thus enabling 
the operator to feed the metal con- 
tinuously, instead of waiting for each piece to come to the top of 
the die and be removed or slid off before the next can be cut. 

Fig. 486 is a vertical section of the lower or die portion, 
showing the die parts in position on the press bolster and the 
lower plunger. Fig. 487 is the upper or punch portion. In Fig. 
486 A is the press bolster, B the raised or bridge bolster on which 
the cutting and drawing die J is fastened, and D the lower 
plunger with the embossing die M. 

The cutting and drawing die J is in one piece. It was a forg- 
ing of mild-steel base and a tool-steel face for the cutting and 
drawing portions. F is the cutting-edge, sheared as shown at 
G ; H the surface on which the blank is held while being drawn ; 
I the drawing-die portion, and X the stripping edge. The die 
is fastened to the face of the bridge bolster by the cap -screw K. 
L is a clearance hole in the bridge bolster. The embossing die is 




FIG. 485. 



INTERCHANGEABLE MANUFACTURING. 411 



secured to the face of the lower plunger by the two screws O. 
N shows the embossing face of the die. 

In the upper part of the punch part, Fig. 487, Q is the com- 




FIG. 

bined drawing and embossing punch, and P the cutting punch 

and blank -holder, which locates on the face of the outer ram of 

the triple-action press at 8 and is 

fastened to it by the cap -screws 

through T. The combined cutting 

punch and blank-holder was a 

forging of mild -steel back and tool- 

steel face, while the drawing and 

embossing punch was drawn and 

worked out of a round length of, 

annealed tool steel. It is secured 

in the inner ram by a key through 

the taper slot. 

It will be understood that very 
accurate work was necessary in 
making the "tools and that all 
working parts were hardened, 
drawn, ground, and lapped to a 

dead finish in order to have the 

. FIG. 487. 

work come out as required. 

The manner in which the tools were used to produce the shell 
was as follows : 




412 TOOL-MAKING AND 

The lower die being fastened to the face of the plunger D and 
the upper die with the bridge bolster to the face of the press 
bolster, the combined cutting punch and blank-holder P is located 
on the face of the outer ram and the combined drawing and em- 
bossing punch in the inner ram. The strokes of the two upper 
rams of the press are then adjusted, and the lower one on which 
the embossing die is located is adjusted to almost meet the face 
of the embossing punch Q on its up -stroke. All is then ready. 
The combined cutting punch and blank-holder Pis worked down- 
ward by the outer ram of the press, and travels slightly in ad- 
vance of the drawing and embossing punch Q which is actuated 
by the inner slide, the outer slide of the press being so adjusted 
that after its stroke has been made it stops during about one- 
quarter of the rotation of the crank-shaft. The blank is cut out 
from the sheet and held between the annular pressure surfaces, 
H of the die and P of the punch, during the down " dwell" of 
the outer slide. Now, while the blank is held under pressure 
which has been regulated to suit the special requirements of the 
metal to be drawn the drawing and embossing punch Q con- 
tinues to descend, draws the metal from between the blank-hold- 
ing surfaces, and draws it into and through the die at I, the 
drawing and embossing punch continuing to descend until the 
shell has been drawn completely through the drawing die, carry- 
ing it down until its lower surface meets the face N of the em- 
bossing die which corresponds in its function to the solid bottom 
in double-action dies mounted on plunger D working in sleeve C 
on its up -stroke. It is actuated, by arrangements at the side of the 
press, motion being communicated through cams on the end of the 
crank-shaft. Here the shell receives on its face the impression of 
the design shown in Fig. 485. On the up-stroke the finished article 
is stripped from the punch Q by the stripping edge X, and, the 
press being inclined, the work slides off at the back. 

It is surprising how much fine work can be got out of a 
triple-action die in a day of ten hours, and it would pay any 
manufacturer who has work of the kind shown here to do in 
large quantities, to adopt dies of this construction, as any of his 
double-action presses can be arranged for them at a small cost 
compared with the increased output. 



INTERCHANGEABLE MANUFACTURING. 413 

In regard to the making of the dies, I might state that they 
are easier to construct than those of the single-action combina- 
tion type which are most frequently used for such work. There 
are fewer parts to the triple-action dies than to the others, and 
there is less liability of their getting out of order, while the 
hardening of the working parts can be done with the assurance 
of success, and the grinding and lapping of the hardened parts 
to the finish sizes afterward can be done with ease. In order 
not to leave any marks on the outside of the shell when drawing 
aluminum, it will be found well to lap the drawing die after 
grinding with a lap actuated in the direction of the working 
movement. 

I neglected to state that it was necessary to lubricate the 
aluminum sheets before working, but as the cleaning of the cov- 
ers afterward would have cost more than the making of them, 
and as the preparation which was to fill the boxes was such as to 
require the entire elimination of oil 011 the metal, we had to be 
very careful in lubricating the sheets so as to get a sufficiently 
thin coating on them to allow of its being taken up in the work- 
ing of the metal. This was successfully accomplished by coat- 
ing one sheet thickly with melted Russian tallow and running it 
through a pair of rolls, after which a number of other sheets 
were run through and coated evenly and thinly. The oil disap- 
peared entirely during the blanking and drawing of the shell. 

The cover was 3J inches in diameter, 1 inch high ; was 
punched from stock slightly over -^ inch thick and required a 
blank 4|| inches in diameter, which left just the narrowest pos- 
sible margin for trimming. 

BLANKING AND DBA WING AN ALUMINUM SHELL. 

Not very long ago I had a set of dies to make for the produc- 
tion of an aluminum box, and as it was necessary to construct 
the tools so that the articles might be produced at the minimum 
of cost, I adopted dies which would allow of producing a cover 
and a box complete at each stroke of the press ; that is, one die 
for the cover and another for the body of the box. These dies 
were of the combination cutting and drawing type, in which the 



414 



TOOL-MAKING AND 



blank is first cut and then held between the annular pressure 
surfaces of the punch and blank-holder ring while it is being 
drawn up into the punch. The shell as drawn to form tlie body 
of the box, and the die used for it are shown in Fig. 488. 

As I have been in a number of shops where they use two dies 
to accomplish results which are attained in this one, and as the 




FIG. 488. 

construction and action of these dies are by no means well known, 
a short description of it may be of interest. 

Fig. 488 shows a longitudinal cross-section of the die com- 
plete as it appears when set in the press and ready for work. 
A A is the cutting-die, a forging of mild steel with a tool -steel 
face to act as the cutting-edge ; G is the drawing punch, which 



INTERCHANGEABLE MANUFACTURING. 415 

is located in the cutting-die by being screwed into a set at E E ; 
D is the spring-pressure attachment plate, to which the cutting 
die is bolted by bolts 00; P P are two of the six tension pins 
which support the blank -holder ring B B and communicate the 
tension from the rubber spring barrel L. The spring-barrel at- 
tachment consists of the stud N which is screwed into a tapped 
hole J in the plate D D, the two cast-iron washers K /f, and 
the rubber spring barrel L. This rubber spring barrel is usually 
about 3^ inches in diameter and 6 inches long, for drawing all 
shells up to one inch in depth. M is the nut for adjusting the 
pressure in the blank while it is being drawn up into the punch. 

In the punch or upper section of the die, F F is the combined 
cutting punch and drawing die. It is a forging of mild steel 
with a tool-steel ring welded on to act as the cutting and draw- 
ing face. H is the drawing-die portion of this punch, G the 
spring pad which expels the shell after it is drawn, and J the 
adjusting nut for the spring pads. In a die of this kind the 
cutting punch, drawing pad, blank-holder ring, and cutting 
die are all hardened and tempered, the cutting-edges being 
drawn to a dark straw and the drawing portions to a light straw 
temper. 

In using a punch and die of this kind the die is first set up 
on the press bolster and the plate D D bolted to same. The 
punch is then located in the ram of the press and aligned with 
the die. After this the stroke of the press is set so that the 
punch will descend the proper distance, the pressure of the 
spring buffer is regulated, and we are ready to proceed. A sheet 
of stock is entered to rest on top of the cutting-die and the press 
stopped. As the press descends, the cutting-edges punch the 
blank into the cutting die A A, where it is held between the faces 
of the punch and the blank -holder ring B B, and as the punch 
continues to descend the drawing punch G draws the metal up 
into the cutting punch and from between the pressure surfaces, 
the metal being held tight enough to prevent inceptive wrinkles 
and crimps from forming. As the punch rises the sheet of stock 
is stripped from it by bent pins placed around the cutting-die, 
and the finished shell is expelled from the inside by the spring 
pad being actuated by a knock-out in the press body. When 



416 TOOL-MAKING AND 

a die of this kind is used to an inclined press the finished shell 
falls off through gravity at the back. 

Combination cutting and drawing dies of the construction 
shown and described here may be used to the best advantage for 
the production of shells from stock as thin as paper up to -J- inch 
thick. They may be used in either single-acting foot or power 
presses. In most cases the shells produced in dies of this kind 
are of shallow shapes, their edges frequently not being over 
gL- inch deep, as for instance, can tops and bottoms, pail, bucket 
and cup bottoms, etc. On the other hand, however, dies of this 
class can be used for the production of much deeper articles, 
such as boxes and covers for blacking, lard, salve, and other 
goods up to f inch deep, or for cutting and drawing burner and 
gas-fixture parts, toys, etc., up to 1 inch in depth. However, 
the best results will be secured in the drawing of shells w r hich 
will not exceed f inch in length, as in order to draw that depth 
the rubber spring barrel has to compress to its maximum, and to 
compress it more would cause the metal either to stretch exceed- 
ingly or to split. When it is desired to draw shells over f inch 
in depth it will be found better to use two dies, a combination 
die and a re-drawing or finishing " push -through" die. 

As the die shown here was for cutting and drawing alumi- 
num, it may be well to assure my readers that no difficulty was 
experienced, notwithstanding that the tools were made the same 
as for working brass. The precaution necessary, however, to 
assure satisfactory results was the use of a proper lubricant, 
which was a cheap grade of vaseline. For deep draws in this 
metal use lard oil. 

A MCE JOB OF BENDING AND FOKMING. 

Fig. 489 shows the blank to form Fig. 491. This blank was 
7 inches long by 2j- inches wide, and w r as of hard brass T 1 g- inch 
thick. The corners were to be sheared to the radius shown, 
three holes were to be pierced at each end, and a slot was to be 
punched in the centre. 

It was considered more economical to shear the strips of 
stock to the required width. The tools, Fig. 492, were of the 



INTERCHANGEABLE MANUFACTURING. 



41 



"gang "type, performing the operations on the blank success- 
ively, and lastly cutting off the piece to the required length. In 
the die section V V indicate two of the piercing dies. They are 



r n 


"^v 




O The Blank 








c 


V 


s 



iG. 489. 



hardened and ground steel bushings let into counterbored seats 
in the cast-iron die-block. X is the slotting die located in a 
channel in the face of the die-block by means of a strong dowel 




FIG. 490. After First Bending Operation. 



at Y. Z is the corner-trimming and cutting-off die, located in 
the die-block in the same manner as the die T. The gauge-plate 
extends along the entire length of the die, while the stripping 



-w-i? 




FIG. 492. 

arrangement consists of four straps fastened by round -head 
screws T. By making the die in this way any injured part 
could be taken out and replaced independently. 

The punch consists of a cast-iron holder in which are located 

27 



418 



TOOL-MAKING AND 



all of the small punches, five of which are fastened in their coun- 
terbored seats by means of set-screws J, while the inner central 
one is fastened by a flat-head screw let in from the back of the 
holder. The slotting punch M is located in a square channel in 
the holder by dowel O and two flat-head screws N N. The 
trimming and cutting-off punch is located in the same manner in 
channel Q Q by dowel E and screws 8 S. 

The slotting punch M is the longest, while the cutting -off 
punch is the shortest. This is so that, the stock being fed from 
left to right, the slotting punch will pierce the stock first and 



PLAN 

OF 
PUNCH 



1OLDER 




FIG. 493. 

locate it while the six holes are being pierced, and the cutting-off 
punch will not commence to cut until all other punches have 
entered their dies. Thus the accurate sizing of the blanks and 
the location of the various operations is assured. With this die 
an adjustable stop, not shown, was used. 

The result of the first bending operation on the blank is shown 
in Fig. 490, and to perform it the tools shown in Fig. 493 were 
used. The sketches are so clear that very little description will 
be necessary. The punch -holder is of cast iron dovetailed on 
the face at K K for the punch of tool steel, which is worked out 



INTERCHANGEABLE MANUFACTURING. 419 

to the shape shown and hardened at the bending face. The 
locater and the spring arrangement are self-explanatory. The 
die also is of tool steel and is machined to fit the bolster and has 
a tapped hole at W for fastening screw. P P indicate the blank 
in position for forming, while the dotted lines V V indicate it as 
formed into the die. 8 S are the side gauges and T the end 
locating point. In use, the press in which the dies were located 
was inclined, and the work after bending fell off at the back. 

For the last operation in the production of Fig. 491 the very 
simple tools illustrated in Fig. 494 were used. The work before 
finishing is indicated by the dark portion in position on the- 




FIG. 494. 

locater L, while the dotted lines P P show it as finished. The 
punch, of tool steel, is machined to fit the dovetailed channel in 
the face of the holder (not shown) and at 1 1 to fit the central 
formed section of the work ; the die is of cast iron. 

The rapidity with which these two bending dies can be 
worked and the quality of the work done by them are surprising 
when the simplicity and cheapness of the tools are considered. 
Some may think that it would have been better to have designed 
a die which would do all the bending in one operation. Possi- 
bly, if a sufficient quantity of the articles were required say 
several millions. 



420 



TOOL-MAKING AND 



"GANG" PUNCH AND DIE FOR PRODUCING 
EYELETS IN ONE OPERATION. 

As an example of what is being accomplished in the devising 
of means for the production of sheet -metal articles in one opera- 
tion I illustrate and describe here a "gang" die of very interest- 
ing type. A number of these dies were designed and pnt into 
successful operation by the writer not long ago for the produc- 




rf I "M 

-. ^7^f^--4--r\ 




tion of one of two parts of a metallic button. They will be 
found the best to adopt for the manufacture of small buttons, 
eyelets, shell rivets, and anything of like nature that it is neces- 
sary to produce cheaply and in large quantities. To secure the 
minimum cost of operation, the stock is usually fed automatic- 
ally by means of a fine-tooth ratchet roll-feed, thus securing fine 
adjustment of the stroke. 

In brass work, where we can get our stock in long lengths, 
or in rolls approximately uniform in width, a die of the type 
shown in Fig. 495 will run off the entire strip or roll without the 



INTERCHANGEABLE MANUFACTURING. 421 

possibility of error, thus allowing of the press attendant looking 
after several presses and keeping them running continually. 

Now, in the first place, be it understood that in order to draw 
sheet metal into any form or shape, it is first necessary to pro- 
vide a blank. And when the article drawn is produced progres- 




FiG. 496. 

sively, as in the die here shown, it is necessary, first, to cut the 
blank partly from the strip so that it may decrease in diameter 
with the drawing in such a manner as in no way to disturb the 
relative distance between the centres of the different operations 
required to produce the shell. This is the point which many 
die-makers forget, so that the dies prove defective where means 
are not provided for first partly cutting the blank, and there is 
no possibility of locating the successive operations in their 
proper positions, because of the metal which goes to form the 
cup being drawn sidewise and lengthwise in the first drawing. 
And as this will continue with each draw, there will be 110 likeli- 
hood of accurately locating the different operations. The way 
in which a "gang" die of this kind should be made in order to 
attain the desired results, will become apparent to the practical 
reader in the description of the tools here shown. 

The punch and die were used to produce small shells like the 
one shown at the upper right of Fig. 495. And it required seven 
workings to produce the shell, finishing it complete from flat 
stock at the rate of 40,000 to 50,000 per day of ten hours. The 
stock used was . 030 soft brass. 

As the illustrations of the die and punch show clearly the 
various parts used in the construction of the tools, and Fig. 496 
the results accomplished at each operation in the progress of the 
strip across the die face, very little description will be necessary. 

The stock is first cut as indicated at A, Fig. 496, by punch J, 
Fig. 495, and then at B by punch K. Thus, the blank is pro- 
duced so as to remain attached to the strip and to allow of being 
drawn and decreased in diameter by the subsequent operations 



422 TOOL-MAKING AND 

"without affecting the position of its centre in relation to the 
strip. This will allow of the metal being drawn into the shell 
and still leave a margin to hold the cups together and allow of 
feeding them along for the next operation. 

The stems of the seven punches J K L M N and P are let into 
reamed holes in the holder I and are fastened with set-screws, 
not shown. The punches were all hardened, drawn, and care- 
fully lapped to size and shape. The die is finished in the usual 
manner, formed counterbores being used to finish the drawing 
and sizing dies. Q is the first cutting die, R the second, 8 the 
first drawing die, T the second, U the third, and V the sizing 
and finishing drawing die, while W is the blanking and trimming 
die. Each of the drawing dies is furnished with a plunger, 
which is hardened and drawn and let into pad T. These plun- 
gers serve the double purpose of holding the metal while being 
drawn and of stripping it from the dies afterward, thereby leav- 
ing the stock free to be fed forward to receive the next opera- 
tion. A channel planed lengthwise in the bolster A- A at Z 
allows the pad T to work up and down with the action of the 
press ram. The two springs B-B B-B keep the plungers up with 
sufficient tension to hold the metal securely between their faces 
and the faces of the drawing punches while the drawing and 
reducing are being accomplished. Their pressure is adjusted or 
regulated by the headless screws D-D D-D. The trimming or 
blanking punch P has a pilot pin which fits the last drawing 
snugly and locates it true and central for being trimmed and 
blanked clean off the strip. 

As the results accomplished by the use of such tools as are 
herein described and illustrated would require three or more 
operations if the simpler tools were used, it is no hard matter to 
figure out what the saving is. 

In conclusion I might state that there is any variety of small 
drawn, formed, or embossed sheet metal work that could be pro- 
duced more accurately and in half the time by the use of just 
such dies as that shown here. In order to succeed with these 
tools, however, always remember, before attempting to draw and 
form cups progressively from the strip, to provide means for 
partly cutting the blanks from which to draw the cups. 



INTERCHANGEABLE MANUFACTURING. 



423 




FIG. 497. 



COMPOUND DIES FOE PAETS OF TELEPHONE 
TEANSMITTEE CASES. 

In Fig. 497 are shown the assembled parts of a telephone 
transmitter case of sheet metal, and in Figs. 498 to 503 the dies 
used for producing the parts. It is needless to state that these 
cases are used in great quantities and that the dies for their pro- 
duction are required to be of the 
most accurate and lasting con- 
struction in order that the parts 
may be produced rapidly and in 
exact duplication. As the work 
involved in the production of the 
transmitter-case parts consists of 
blanking, drawing, forming, pierc- 
ing, and wiring, the dies are in- 
teresting, and engravings of them, 
together with the description of 
their construction and operation, 
will prove suggestive in the adoption of similar tools for the 
production of ajarge variety of drawn sheet-metal work, accu- 
rately and economically. 

As will be seen from Fig. 497, the case consists of three parts, 
designated 1, 2, and 3, respectively. The part 1 is of an artistic 
shape and represents a nice job in drawn work. The die used 
for producing it is shown in Fig. 498 and was, as were all the 
blanking and drawing dies used in the production of the case 
parts, of the compound double-action type of construction. As 
a great many tool -makers are not familiar with drawing dies of 
this type, a slight description of their use will contribute to an 
intelligent understanding of their making. 

Double-action dies derive their name from the fact that they 
are used in double-action presses to cut a blank and at the same 
stroke draw it into shape without the help of springs or buffers, 
as in the case combination single-action dies. The kind and 
thickness of the metal used determine whether one or several 
operations will be necessary to obtain the desired shape and' 



424 



TOOL-MAKING AND 



depth in the article. There are two essentially different types 
of double-action dies, viz., Fig. 498 is a "solid-bottom die/' and 
Fig. 501 a " push-through die." However, they are both used 
in the same way. 

Taking the die Fig. 498 which was used for producing the 
part 1 of Fig. 497 G is the die bolster, in which the drawing 
and blanking dies are located. It will be understood that all 
parts of this die had to be constructed very accurately, that the 
working parts were hardened, drawn, and ground and lapped 
smooth in order to produce the parts as required. In the die, A 




FIG. 498. 

is the main drawing die, which is located in a taper seat in the 
bolster, while F F is the blanking die, located in a seat in the 
surface of the bolster and secured by means of the two fillister 
head-screws H II. Nis a stripper of the usual type. 

In the punch section, L L is the combined cutting punch and 
blank-holder ; a forging of mild steel with a tool-steel ring welded 
on to one side to act as the cutting punch I L It was machined 
all over; being turned at J Jto locate on the face of the outer 
ram of the double -act ion press, and was hardened and drawn at 
1 1 and then ground to fit the cutting die F F, after w r hich the 



INTERCHANGEABLE MANUFACTURING. 425 



face was lapped so that the blank would be held evenly while 
being drawn. B is the drawing and forming punch and E its 
stem. The manner in which this die was used, as well as the 
other double-action dies shown here, will be understood from 
the following : 

The lower or die section G is fastened to the face of the press 
bolster, while the combined cutting punch and blank -holder 1 1 
is fastened to the face of the outer ram, and moves slightly in 
advance of the drawing punch B, the stem K of which is fastened 
in the inner ram, by which it is actuated. The outer ram of the 




FIG. 499. 

double -action press being so arranged that, after making its- 
stroke, its stops during about one-quarter revolution of the 
crank-shaft, and the combined cutting punch and blank-holder 
cuts the blank at F F, carries it down to the inner surface of the 
cutting die ; holds it there tightly and remains stationary, hold- 
ing it between the annular pressure surfaces of the punch and 
E E during the down "dwell" of the outer slide. 

While the blank is under a pressure which has been regulated 
to suit the special requirements of the case, the drawing punch 
B continues its downward movement, thus drawing the metal 
from between the pressing surfaces into the shape required. As 
the punch rises the combined blank-holder and cutting punch 
remains stationary until the drawing punch has disappeared 
within it ; then it rises also. At the completion of the up -stroke 
a knock-out attached to the press actuates the die knock-out I) 
which delivers the finished shell at the top of the die. Some 



426 



TOOL-MAKING AND 



very close work and careful grinding, lapping, and polishing 
were necessary in order to get this die to produce part 1 as was 
desired, the metal used being sheet brass ^ inch thick, the utmost 
care being necessary to get the difference in the diameter and 
curves and shape of the punch and die exactly two thicknesses 
of metal. 

The punch and die used for producing part 2 of Fig. 497 is 
shown in Fig. 500. Although a compound double-action die, it 
will be seen that it is constructed differently from the one shown 
in Fig. 498, and that different results are accomplished in it. In 
this die the shell, forming part 2 of Fig. 497, is blanked, drawn, 
formed, and a hole pierced in the centre, to admit the end of part 




FIG. 500. 

3 as shown at a, Fig. 497, at one stroke of the press. However, 
the use and operating of the die are the same as explained for the 
first. As in the other, close and careful work were necessary 
on all the parts in order to have the die work well in the press. 
In the die section, E E is the cast-iron bolster, P P the combined 
cutting and drawing die, and Q Q the combined bottom-forming 
and hole- piercing die. 

In the upper section of die, Fig. 500, W W is the combined 
cutting punch and blank-holder, a forging T T the drawing and 
forming punch, and ZJthe hole-piercing punch. The manner in 



INTERCHANGEABLE MANUFACTURING. 



427 



which the metal is cut, drawn, formed, and the hole pierced, 
may be seen from the dark section. In this die the bottom-form- 
ing and hole-piercing die Q Q also acts in the capacity of a 
knock-out ; it being actuated on the up-stroke of the press rams by 
the knock-out device attached to the press. The blank produced 
by the hole-piercing punch U finds egress through an enlarged 
hole running entirely through the stem of the piercing-die sec- 
tion. Ideal results may be accomplished in a die of this con- 
struction, as the holding of the blank while it is being drawn is 
perfect ; an even pressure being maintained all the time, which 
is not the case when single-action combination dies are used, as 
the tension on the blank is communicated through a rubber 
spring barrel which compresses as the blank-holder ring de- 
scends and thus renders the tension uneven. Thus, deep draws 




FIG. 501. 

cannot be attained in a single-action die through the metal tear- 
ing or splitting because of too much pressure on the blank as 
the draw nears completion ; while in compound double-action or 
triple-action dies, draws of considerable depth, in comparison 
with the diameters, can be attained because the pressure on the 
metal is exerted by cams on the crank-shaft and is, of course, 
even. 

To produce part 3 of the case, to the shape shown in Fig. 497, 
three operations were necessary. The first consisted of drawing 



428 



TOOL-MAKING AND 



a shell of the shape shown at the upper left of Fig. 501. This 
shell was blanked and drawn in the double-action a push- 
through^ die shown in Fig. 501. As will be seen, the die sec- 
tion is in one piece. It was a forging of mild steel at base, with a 
tool -steel face for the cutting die. The weld of the two steels is 
indicated by a wavy line in the drawing. The machining and 
finishing of the die were accomplished in the usual manner ; all 
working parts being left over size, and ground and lapped to a 




FIG. 502. 

finish after the die had been hardened and tempered. A is the 
base, C C the cutting die and blank-holder portion, D D the 
drawing die, and B B the stripping edge. 

In the punch section of Fig. 501, II is the combined cutting 
punch and blank-holder and /the drawing punch. As will be 
seen, the die is equipped with a stripper of the usual construc- 
tion. This die was a far more rapid producer than the other 
two, as the metal was cut, then drawn and pushed through the 



INTERCHANGEABLE MANUFACTURING. 429 

die, stripping at B B ; thus obviating the necessity "of a knock- 
out and the delivering of the drawn shell at the top of the die. 

The second operation in the production of part 3 was accom - 
plished by means of the tools shown in Fig. 502. These tools 
require little description as their construction and use are al- 
most evident at a glance. S is the punch -holder, P the drawing 
punch, and R its stem ; while X is the inside blank-holder which 
supports and holds the shell on the inside while it is being reduced 
and formed ; Q is the stripper. In the die, L is the bolster, M 
the die, and Nthe knock-out for stripping the finished work from 
the die. The punch and die were operated in a reducing press 
with a stroke of considerable length. 

The last operation in the production of part 3 consisted of 
punching out the bottom at b b and wiring the edge at d d as 
shown. This work was accomplished entirely by the use of 
the combination wiring and piercing die shown in Fig. 503. 
Although the drawing is very clear, a description may assist 
many to understand intelligently the construction and working 
of the tools. 

In the lower section, T is a cast-iron bolster, bored out and 
recessed for the hole-piercing die U 7 and the holder and locator 
V ?. The piercing die was of tool steel, hardened, ground, and 
lapped to size, and a force-fit into its seat in the bolster, while 
V V was of mild steel worked out on the inside to fit the formed 
shells and turned taper on the outside to drive into the taper seat 
in the bolster. 

The upper section consists of, first, the holder _B, a forging of 
mild steel worked and machined as shown, to contain the wiring 
die W W, the spring stripper and work supporter X. JT, and the 
piercing punch T. As will be seen, the wiring die is located in 
a seat in the holder-face and fastened by means of fillister head, 
screws, while the piercing punch is located in a reamed hole run- 
ning entirely through the holder, and is permanently secured in 
position by means of a taper pin at A. The spring D D exerts 
enough pressure on the combined work-supporter and stripper 
X X to allow of it supporting the shell on the inside while it is 
being wired by the die W W, and then stripping it from the 
piercing punch at the rise of the press ram. 



430 



TOOL-MAKING AND 



When the punch and die are in use, the shell is slipped into 
the locating seat in V V and the press stepped. As the punch 
descends, the supporter and stripper come in contact with the 
inside of the shell and hold it tightly while the spring com- 
presses and the rest of the punch parts continue to descend. 
Then the edge of the shell enters the wiring groove and follows 
around its curves ; the punch descending until the curl is com- 
plete, the piercing punch Y having meanwhile punched the bot- 
tom out of the shell and into the die U. At the up -stroke of the 
ram the stripper X X remains stationary until the piercing punch 




FIG. 503. 

has left the shell and the wiring die has risen above it ; then it 
rises also, leaving the finished shell in a position to be easily 
removed. 

The other operations necessary to allow of the parts of the 
transmitter case being assembled as shown in Fig. 497 consisted 
of joining parts 3 and 2 together as shown, and piercing four 
holes in the rims of parts 1 and 2 for screws. But as the tools 
used for those latter operations were very simple, their illustrat- 
ing and describing are unnecessary. 

In conclusion, I might state that it would be well for manu- 



INTERCHANGEABLE MANUFACTURING. 431 

facturers of artistic drawn sheet-metal articles and parts to give 
more attention to the use of double-action dies and double-action 
presses, as the results accomplished by their use are not to be 
compared with those accomplished by combination dies in single - 
action presses. 



CHAPTER XXVII. 

Processes, Presses, Devices, and Arrangements for 

the Rapid and Economical Manufacture 

of Sheet-Metal Articles. 

PEESS WOEK. 

IT is only during the past few years that the use and value of 
the power press and hydraulic press for sheet-metal working have 
come to be almost universally appreciated and known, and to-day 
the rapidity with which their use is being extended is astonishing. 

Among the machine-tool brood the power press and its work 
occupy a unique position in one respect, as it is the only ma- 
chine tool, and its operation involves the only process, in which, 
after the material is once cut off from the sheet or bar, there is 
no making of chips or waste. The press, as such, does neither 
cutting or abrading. 

To be sure, the power press is usually a more or less expen- 
sive machine, and the devising and constructing of suitable dies 
for it requires the employment of the most skilful mechanics and 
is often among the most expensive work of the trade. But when 
the machine and dies are in successful operation the saving of 
labor in production is enormous, and is greater than that saved 
by any other machine tool. In fact the most elaborate and costly 
articles are often numerously produced by the power press, which 
could not be made by other processes for one hundred times or 
even one thousand times the cost. 

Until lately the power press, by reason of its rapidity of pro- 
duction and the m unfolding of its product, was distinctly a fac- 
tory machine. But to-day this same machine is employed almost 
universally in up-to-date machine shops for the production of an 
endless variety of parts which are used on machines, and it is to 
be reckoned with the same as the other machine tools ; that is, as 
an economic producer of shop products. 

432 



INTERCHANGEABLE MANUFACTURING. 433 

PEEFOEATING FLAT AND CYLINDRICAL SHEET 

METAL. 

In the production of plates and articles with numerous per- 
forations, dies accompanied by novel mechanical devices play a 
more important part than any other line of sheet-metal work. 
While the dies used in such work are comparatively simple, the 
devices and appliances used in connection with them are often 
intricate and noA 7 el. Especially is this so in the perforation of 
cylindrical articles and parts, where the die remains stationary 
and the shell is rotated successively at each stroke of the press, 
until the entire surface has been worked upon. By means of 
these rotating devices shells may be perforated in any design or 
pattern of perforations by means of a single row of dies, the 
manner in which the shell is rotated after each stroke determin- 
ing the pattern of the perforations. Anyone who has noticed 
the odd, novel, and artistic designs in the perforated shells used 
on gas and lamp burners and fixtures must have wondered how 
they can be produced so cheaply. The secret lies principally in 
the devices used for rotating, and farther on I show a number of 
such devices and the dies and tools used with them. "" 

In the perforating of flat sheets of metal the construction of 
the dies used is equally similar to that followed out in the " gang " 
types, and they are used on work ranging from ornamental sheet- 
metal articles to the punching of holes in steel beams and boiler 
plates. The holes pierced with this type may be of any shape 
desired and may be spaced in any manner or combinaton. Often 
the usual conditions are reversed and instead of the perforations 
being desired, small blanks are the objects sought, a number of 
them being fed to the dies automatically. Perforated sheets of 
the different metals are now in great demand and are used for a 
variety of purposes too numerous to mention. 

ATTACHMENTS FOE CYLINDRICAL PEEFOEATING. 

In Fig. 504 is shown a horizontal two-slide foot press for 
punching simultaneously two holes or slots on opposite sides of 

drawn shells. The die is located in the centre and is made with 

28 



434 



TOOL-MAKING AND 



cutting-edges on opposite sides and with a clearance hole through 
the bottom as an escape for the scrap or punchiugs. The punches 
are of steel rod fastened in punch-holders or chucks which are 
adjustable and mounted on slides provided with adjustable gibs. 
Each slide is arranged with an adjustable stop to allow r of pierc- 
ing shells of different diameters. Dies of this type, when used 
in a machine of the kind shown, are very convenient for rapidly 
and accurately producing pierced shells for lamp-burners, satchel 
locks, and a variety of other pierced work requiring holes pierced 
on opposite sides. 

Figs. 505 and 506 show two different sets of perforating fixtures 
in position on presses for perforating burner shells and other 




Fir;. f,;4. 



FIG. 505. 



cylindrical sheet-metal articles. Fixtures of these types are used 
extensively for work which it is desired to perforate all around, 
although sometimes used to perforate in sections only. 

The attachment shown on the press in Fig. 505 is used for 
taper and crowning shells, which necessitates the setting of the 
die-holder and rotating device at an angle with the lower face of 
the slide. The shell, as perforated, is shown on press bolster at 
the right. 

Fig. 506 shows a press equipped with dies and fixtures for 
perforating small close patterns in bottomless shells. As will 



INTERCHANGEABLE MANUFACTURING. 



435 



be seen from the engraving, in which a die, punch, and two per- 
forated shells are shown on the floor, the die is a piece of steel 
with two rows of holes in it and dovetailed into the work-holder, 
while the punch is equipped with a spring stripper and two rows 
of piercing punches. The dies shown located in the press are 




FIG. 506. 

for perforating the small shell, and the ones on the floor for per- 
forating the large one shown at the right at the bottom. 

In the attachments of the types shown in Figs. 505 and 506 
the perforating dial with a chuck of suitable shape is mounted 
011 a die-holder, and a ratchet having teeth spaced to suit the 
holes or pattern desired is mounted and arranged to rotate the 
shell at each stroke of the press. By the use of such attach- 



436 



TOOL-MAKING AND 



ments, perforating may be done at the rate of 150 to 200 strokes 
per minute. 

The adjustment of the parts of these perforating attachments 
is easily and quickly made, so that but a short time is required 
to change the attachments from one style of shell to another. 
Presses in which such attachments are used are often provided 




FIG. 507. 



with a latch lock for the clutch connection, which is automatic- 
ally released after each complete rotation of the article on the 
perforating chuck, thus stopping the press automatically after 
the requisite number of strokes have been made. 



INTERCHANGEABLE MANUFACTURING. 437 



PIEECING AND BLANKING SMALL AEMATUEE 

DISKS. 

In Fig. 507 is shown a set of dies as located in an adjustable 
press for accurately piercing and blanking armature disks for 
small generators and motors. The press is furnished with an 
automatic knock-out, and its inclined position allows the blank, 




FIG. 508. 

after being punched and pierced, to be lifted out of the die and 
slid off at the back. The pierced blanks are usually punched 
from strips sheared to the necessary width. The construction of 
the dies is such as to allow the outside and the inside to be 
punched simultaneously, after which it is held between the faces 
of the blanking punch and the pad, and descends far enough for 
the piercing punches located around the die to pierce holes. 
The finished disks are shown beneath the press. 



438 TOOL-MAKING AND 

KEEPING SHEETS OE AETICLES STEAIGHT WHILE 
PEEFOEATING. 

For perforating articles of considerable size, or flat plates 
which are required to be kept straight, dies of the usual con- 
struction will not do good work, as on such dies stationary strip- 
pers are used and they are liable to distort the metal to such an 
extent as to require subsequent straightening. To overcome this 
defect a press equipped with a cam-actuated stripper should be 
used, especially on accurate work, such as parts of clocks, elec- 
trical instruments, etc. A press equipped in this manner is 
shown in Fig. 508. The stripping device is such as to leave a 
clear space between the punch and die, thus allowing the oper- 
ator to manipulate and observe the work at will. The action of 
the stripper when the press is running is as follows: The strip- 
per plate strikes the blank or article first, straightening and 
clamping it before the punches enter, and holding it under 
pressure while the punching and stripping are being accom- 
plished. In this manner the flat or formed piece comes out per- 
fectly straight and true. The punches used when a press is 
equipped with a stripper of this type may be made considerably 
shorter than where a die with a stationary stripper is used, thus 
making them more durable. Also by this arrangement a smaller 
hole in proportion to the diameter of the punches may be pierced, 
through the support given the punches by the movable stripper 
up to the point where they enter the stock. 

PEEFOEATING LAEGE SHEETS OF METAL IN 
SPECIAL DESIGNS. 

For the perforating of large sheets of metal in designs simi- 
lar to those shown in Figs. 509, 510, and 511, special feeding 
arrangements are used. Some of the patterns are staggered and 
others are regular, and to produce them a single row of "gang" 
punches and dies or a double row is used. When a double row 
or "gang" of punches and dies is used, the metal is usually fed 
automatically by means of a roller feed to a press of large and 
powerful construction. The construction of the punches and 



INTERCHANGEABLE MANUFACTURING. 



439 



dies for such work is such as to allow of removing any one or a 
number without disturbing the others. The punches are usually 
located in a cast-iron holder which is fitted to a dovetailed chan- 
nel in the face of the press ram. They are short and stocky and 
fastened by set-screws. The dies are usually tool-steel bushings, 
hardened and ground, and let into holes drilled and reamed in a 
bolster of similar make to that used for the punches. The bush- 
ings also are fastened by set-screws. With a powerful press 




FIG. 509. 



FIG. 510. 



FIG. 511. 



equipped with proper feeds and punches and dies the author has 
seen 154 f -inch holes punched in -inch plate at each stroke of 
the press. The press referred to was used in the works of a 
large agricultural machinery concern and was provided with a 
roller feeding attachment consisting of four adjustable rolls, 6 
inches in diameter and 54 inches long, which fed the stock auto- 
matically in multiples of sixteenths of an inch up to four inches. 
For heavy work the press was provided with back gears, which 
were thrown out when doing light work, so as to give the press 
a higher speed. The slide adjustment on this press was such as 
to allow of raising or lowering it to overcome the shortening of 
the punches through wear. 

PEODUCTION OF PEEFOEATED METAL BY THE 
ALLIS-CHALMEES COMPANY. 

One of the largest producers of perforated metal in the world 
is the Allis- Chalmers Company, of Chicago. In their shops im- 
proved machinery is being constantly provided for the produc- 
tion of perforated metal in the endless varieties which modern 
demands necessitate. The chief aim in this plant is to produce 



440 TOOL-MAKING ANT> 

the material at the lowest cost and in the shortest time possible. 
This object, of course, can be attained only by keeping the 
machines constantly producing perforated sheets of the same de- 
sign and pattern. Most of the output in this line produced in 
the above-mentioned shops is used for rotating screens for stone, 
grain, coal, ore, etc., the perforated plates being rolled to exact 
diameters in special machines. For such purposes perforated 
metals have superseded and are far superior to wire cloth ; being 
much stronger, more uniform in size of hole and niesh, less 
liable to tear or rust out, and in case of breakage they may be 
easily repaired or replaced without affecting the entire sheet. In 
screens for various purposes it is often desirable to arrange them 
with portions left blank. This can be easily done when perfor- 
ated metal is used, as the sheets can be perforated in a press 
equipped with a feed which can be adjusted to feed unequal 
spacings. 

HOBNING AND SEAMING PBOCESSES. 

In the manufacturing of pieced sheet- metal ware, the proc- 
esses of " horning" and "seaming" play a very important part, 




FIG. 512. 



and a large variety of ingenious devices and fixtures is used, giv- 
ing rapid and accurate results. The processes are essentially 
assembling and preparing ones, as they assemble flat, round, and 



INTERCHANGEABLE MANUFACTURING. 



441 



irregular parts, and often prepare them for subsequent opera- 
tions of wiring, curling, etc. The successive stages of a "lock" 
seam are shown in Fig. 512 and a press equipped with the tools 
in Fig. 513. The manner in which an inside or an outside seam 
is finished is shown, two blows being necessary for each. The 
first operation is the forming of 
the hooks, and the second the 
crushing down and locking to- 
gether. There is a large variety 
of work which requires finishing 
with locked seams of this kind. 

For the double -seaming of 
bottoms, tops,' and parts of 
round bodies together, the work 
is accomplished by special ma- 
chinery and dies are dispensed 
with. A machine for this work 
is shown in Fig. 514 and dia- 
grams of the work done on it 
in Figs. 515 and 516. These 
machines are used extensively 
for double seaming "flat bot- 
toms" on to tea-kettles, coffee- 
pots, pails, and similar goods in the tin and enamelled iron- 
ware line. 

The lower spindle carrying the "inside chuck or roller "is 
mounted on a sliding plate, which is drawn forward for putting 
on and taking off the articles. In the case of flaring pails, dish- 
pans, and other articles which are smaller at the bottom than at 
the top, the double seaming is done against a solid plate of the 
size of the bottom, mounted on the sliding spindle. For buckets, 
cups, and other straight articles collapsible chucks are used. 
These chucks are so made that they spread to fit along the edge 
of the bottom when the article is carried up against the upper 
chuck, and fold together after the work is done to permit the 
rapid and easy removal of the seamed article. 

For double-seaming bottoms or tops stamped or drawn with 
a burred edge, as per Fig. 517 and 518, a fixture called a deflect- 




FiG. 513. 



442 



TOOL-MAKING AND 



ing device is required and may be readily attached to the ma- 
chine. The diagrams show the steps in which the seaming is 
done; the deflecting device performs the second of the three 




FIG. 5H. 



INTERCHANGEABLE MANUFACTURING. 



443 



operations. The use of burred-edge blanks for the bottoms of 
round work offers the advantage of easily centring the bottoms 
on the bodies. For a great many articles, however, plain bot- 
tom blanks are preferred. In that case the deflecting device is 
dispensed with, and instead of it two brackets are attached to the 





FIG. 5.5. 



FIG. 516. 



machine, carrying three adjustable rolls for centring the blanks 
or bottoms on the bodies, before clamping. For heavy stock it 
becomes necessary sometimes to have a slight depression in the 



First Step 



Burred Edge Top 





FIG. 518. 

centre of the bottom blank corresponding with a slight projec- 
tion on the clamping plate, so as to prevent the pressure of the 
seaming rolls from pushing the bottom away from its central 
position. 

For a certain kind of work a press specially equipped with 
an automatic fixture for double horning or seaming is used. By 
means of this automatic fixture the two corner seams on large 
square cans having round corners with seams in the centre, may 
be closed at one blow. Tins with sharp corners require a " coax- 
ing " operation on a single horn to start the seam over before 
setting over on a double -horn press. The horn, which is movable 



444 



TOOL-MAKING AND 



in ways, has two working surfaces, the upper one being acted 
upon by a " force" bolted to the press slide, while the lower one 
in descending with the slide acts against a stationary force fast- 
ened to the bed. It will be understood that the two body-halves 
of the can, loosely hooked together, are pushed over the sliding 
horn, as shown in Fig. 519, which, by means of adjustable 
gauges, secures accurate size and position. By the use of a 




FIG. 519. 



FIG. 530. 



double -horn machine the capacity of the operator is nearly 
doubled as compared with what can be done on an ordinary 
horn press. Presses equipped with fixtures for double seaming 
are used extensively for seaming 5 -gallon petroleum cans, as 
per Fig. 520. 

Double-seaming machines (Fig. 521) for seaming articles of 
irregular shape differ from those of the type shown in Fig. 514 
in that they allow the seaming rolls to follow automatically the 



INTERCHANGEABLE MANUFACTURING. 445 

shape of the can. As they do the seaming at the top of the can, 
they are preferable for filled cans. In action, the pressure on 




FIG. 521. 



the foot treadle, which causes the pressure plate to clamp the 
can and lid against the chuck, also throws in the friction clutch 
which starts the work. The double -seaming rolls, controlled by 



446 TOOIj-MAKING AND 

a cam made in a piece with the chuck and finished to the shape 
of the can, follow the shape of the can automatically, while the 
necessary pressure to form and finish the seam is imparted by 
the handles. These pressure handles in such machines are so 
arranged as to relieve the hand of the operator from all vibra- 
tions 'due* to the irregular shape of the cans. Adjustments for 
different heights of work can be readily made by means of a 
hand-wheel, and for different shapes by exchanging the can 
chuck, which can be done in a few minutes. 

The rolling of seams on square cans is usually accomplished 
in the following manner : The can is firmly held between two 
disks made exactly to fit the heads of the can ; the upper disk 
being mounted on a vertical shaft fastened rigidly to the upper 
part of the main frame of the machine and the lower disk to a 
shaft passing through the lower part of the frame and prevented 
from turning by an arm running in the guides, but capable of 
vertical motion imparted to it by a cam on the treadle shaft. 

The steel rolls which operate on the seam at the top and bot- 
tom are carried by a frame which rotates upon the upper and 
lower stationary shafts and revolves around the can. These rolls 
are mounted on levers pivoted in the rotating frame, the oppo- 
site ends of the levers being finished with rolls bearing against 
star-shaped stationary cams in two vertical shafts which gives 
the "in-and-out motion" required in passing around the corners 
of the cans. The rotating frame carries two sets of these rollers, 
which press upon opposite sides of the can at both top and bot- 
tom, thus equalizing the side pressure and rolling the seams more 
perfectly than would be possible by the use of the single set of 
rolls, each seam being rolled twice in each revolution. There 
are additional cams provided which, as the machine comes to a 
rest, move the rolls outward from the surface of the cam, so that 
the latter may be removed from the machine. Attached to the 
bottom of the rotating frame is a bevel gear meshing with a pin- 
ion on the pulley-shaft. The pulley is provided with a friction 
clutch controlled by the treadle. 

A cam being placed upon the lower disk, the foot treadle is 
pressed and the can is raised and clamped firmly between the 
upper and lower disks. The clutch is then thrown in, and the 




INTERCHANGEABLE MANUFACTURING. 447 

roller frame makes one revolution around the can, the latter 
remaining stationary. After completing the one revolution the 
clutch is automatically released, the rolls are thrown outward 
and the lower disk drops, leaving the can free to be removed. 
The capacity of these machines is from 9,000 to 12,000 cans in 
ten hours, and the saving of solder alone by the use of each ma- 
chine amounts to from $15 to $18 per day. 

For double-seaming the bottoms on large heavy work, such 
as foot-tubs, bath-tubs, wash-boilers, cauldrons, and other large, 
oval, oblong, or square articles, when the bottoms are required 
to be fastened without the usual recess next to the double seam, 
a large machine of special design is used. 

In this machine a high chuck is used, fitting the inside of the 
article, and the double -seaming is done against the inside of this 
chuck. In order to establish the correct position of the bottom 
blank in relation to the body, the blank is usually stamped with 
a slight depression at some distance from the edge, which fits a 
corresponding depression in the top of the chuck. To facilitate 
the taking off of high articles, there is usually an upper arm on 
the machine which carries the clamping-plate that is arranged 
to swing out of the way. 

For the double-seaming of tops, bottoms, or parts of special 
shaped articles, special chucks and devices are necessary ; how- 
ever, the principles involved are all very much the same in all 
work of this class, and a knowledge of the methods in general 
use will enable anyone to accomplish the desired results without 
trouble. 

CUELING AND WIRING PEOCESSES. 

I will here take up a class of press tools and fixtures to ac- 
complish results in sheet metal which a few years back were pos- 
sible to attain only by spinning. The operations in which these 
tools are used are curling and wiring operations, respectively. 
Curling is producing a curled edge around the top of any formed 
or drawn articles of sheet metal. Wiring is the curling of the 
top of such an article around a wire hoop when it requires stiff- 
ening. The tools used for either curling or wiring are of almost 
the same construction. 



448 



TOOL-MAKING AND 



Curl Started 



Half Curled 



In straight work and work but slightly flared simple dies can 
be used to turn the metal, when wiring, around the wire and 
under it, perfectly at one stroke of the press. From 2,000 to 
8, 000 pieces can be wired per day of ten hours. 

Figs. 523, 527, 530, and 531 show cross-sections of dies which 
may be used for curling the edges of circular drawn shells. Of 
course, it is impossible to see the action of the metal in work of 
this kind while the die is working, but by noting the condition 

of the shells at intervals daring the 
curling, by working the die down and 
up by hand, the process can be seen 
and understood. The groove in the 
upper die (or lower die, as the case 
may require) must be finished at the 
back to a perfect half -circle of the 
radius required, and must be lapped 
and polished until free from all cuts 
and scratches, in order to get a clean, 
smooth curl. The sketches in Fig. 
522 show how the upper die curls the 
edge of a half-round shell. In the 
first stage A the metal has commenced 
to curl ; at the next stage B the metal 
has curled to a half-circle of the width 
of the curling groove in the upper 
die. At C the third stage is shown ; 
the punch continuing downward; as 
the edge of the shell passes the centre 
of the curling groove the pressure is 
exerted on the top of the half-round 
curled edge and causes the metal to curl further around until 
the circle is complete, as shown at D. In this manner only one 
operation is necessary to curl the edge of a shell of the type 
shown, as the metal once started around the curling groove of 
the upper die will follow the curl on the same radius as long 
as the pressure continues, or until the edge strikes the side of 
the shell, when it will curl within the first curl. Thus a 
shell may be quarter curled, half curled or completely curled 




FIG. 522. 



INTERCHANGEABLE MANUFACTURING. 449 



by the same die, according to the length of stroke to which the 
die is set. 

When the edge of a shell of the shape shown at Fig. 524 is 
desired to be curled as shown at 526 the work will require two 




The Work 



<^^^^y j ^^x^-xx 




PIG. 523. 



dies. The first die is to bend or form the edges to the upright 
position and the second die to curl the edge. This second die is 




FIG. 534. 



shown in Fig. 527. The upper die is made so as to make the 
entering of the edge of the shell positive within the curling 





FIG. 525. 



FIG. 526. 



groove, and also so that the straight inner wall will hold the wall 
of the shell while the edge is curling, thus preventing any bulg- 
29 



450 



TOOL-MAKING AND 



ing during the process, which would occur if the inside of the 
tool was finished like the outside. In this manner the metal is 
held tightly, and as the ram descends it must follow the shape of 
the curling groove. 

The curling of the edges of drawn shells by means of dies of 
the above type is done in endless variety ; the articles worked 




upon ranging from shoe eyelets to bath-tubs, of both round and 
irregular shapes. The design and construction of the tools de- 
pends on the shape, the thickness of metal, and the diameter of 




FIG. 538. 

curl required ; however, the principles of construction involved 
are the same in all of them. 

The tools in Fig. 530 show how shells of different shape may 
be curled. For the operation shown at A and B a combination 
die and a bending die, respectively, are used. The curling as 
shown at C is done in the die shown. 



INTERCHANGEABLE MANUFACTURING. 



451 



The manner in which curling dies are used for " wiring " on 
both large and small work will be understood from Figs, 531 
and 532. 

Dies of this type may be used for "wiring" or simple "curl- 
ing " on round or oval shells, as long as they are straight or 





FIG. 529 a. 



FIG. 529 b. 



nearly straight w r alled, and are properly supported during the 
process. A tool-steel ring A is attached to the punch-holder. 
The inner diameter of this ring must lit accurately the inside of 




FIG. 530. 

the shell to be wired, so as to prevent bulging or crimping of the 
walls. When "wiring," the ring B is used in the lower die. 

When the dies are in use a wire hoop, which fits the outer 
diameter of the shell, is placed in position on the ring B and 
around the shell which is located within the dies as shown. The 



452 



TOOL-MAKING AND 



ram then descends and the edge of the shell is curled around 
the hoop, enclosing it within it, as shown at the bottom of 
the cut. 

A curling punch and die for curling deep shells or articles 
of thin sheet metal, and a section of the press in which it was 





YlG. 5:31. 



used, are shown in Fig. 533. The punch is located and fastened 
within the ram, while the die is on a sliding table which may be 
pulled back and forth by the operator. The horn or die for 




FIG. 532. 



locating the work is of slight taper, and consequently a solid one- 
piece curling punch can be used, as the decrease in diameter 
when curling is so slight that contraction of the curling ring is 
unnecessary. When in use, the table on which the horn or die 



INTERCHANGEABLE MANUFACTURING. 453 

is located is pulled out to allow the article to be slipped over it. 
This is done, and the table is moved back to place against the 
stop shown. The punch then descends and the edge of the 
article is curled. The punch ascends, the table is pulled out, the 




FIG. 533. 

work is removed, another piece is located, and the operation is 
repeated. When a press with an automatic die slide is used the 
curling or wiring is done more rapidly. 

MANUFACTURING ARMATURE DISKS AND 
SEGMENTS. 

The adoption and use of dies, power-presses, and special sheet- 
metal working machinery for the economic production of parts 
of electrical apparatus has had great development during the 
past few years ; so that to-day establishments that manufacture 
sheet-metal working machinery dispose of a great portion of 
their product to electrical machinery manufacturing concerns. 
One has only to examine an electrical device or a machine to 
realize what a factor the power-press has become in their pro- 
duction. The parts of electrical apparatus for the production 
of which such machinery is used most extensively, are armature 
disks and segments for motors. It is at once obvious that the 
requirements for such work have led to the designing of dies, 
presses, and special machinery which differ in essential details 
from those used in the general and more familiar classes of sheet- 
metal working. 



454 



TOOL-MAKING AND 



An armature consists of a wired u core" composed of tliiii 
sheet-iron plates or disks averaging from .010 to .040 thick and 
10 to 100 inches in diameter. In many of the best armatures the 
disks are produced by punching the centre hole, key slots and 
notches, or winding slots, simultaneously at one stroke of the 
press. The small sizes are thus produced in dies, while the 
larger ones are produced in sections or segments of as large 
size as it is possible to procure iron for. In the cheap and 
inferior armatures the disks are first punched from plain sheets; 
the punching of the centre holes and the key slots is a second 




operation, after which the disks are assembled on shafts, the 
outside turned to the required diameter, and the slots milled on 
a universal milling- machine. 

Machines and dies used for cutting and perforating armature 
disks and segments differ according to the size and shape and 
number or quantity required. There are in general use four 
methods for cutting armature disks. On the size and quantity 
of disks desired depends the practical value of each. 

Disks of very large diameters, or those required in relatively 
small lots, are usually first cut plain by shearing the outside cir- 
cle and afterward the inner circles on circular shearing machines 
of the type shown in Fig. 534. As shown, the lower cutter is in 
an angular position relatively to the upper, so as to permit the 



INTERCHANGEABLE MANUFACTURING, 455 

making of as cleau a cut ou the inside as on the outside. Disks 
cut in this manner are afterward notched on an automatic notch- 
ing machine of the type shown in Fig. 535. A plain blanking 
or notching punch and die are located in the press portion at the 
left and a circular disk clamped between the two pads of the 
indexing and revolving the mechanism at the right. The index- 
ing is entirely automatic, the spacing and number of notches in 
a disk depending on the arrangement of the gearing. 

In this machine the adjustment for different diameters is 
made by simply turning the hand -wheel shown. The adjust- 




FIG. 535. 

ment for different numbers of notches is effected by means of 
the change gears shown, instead of a pawl and index-plate device 
as is usually employed. Each set of gears can be arranged to 
answer for three different numbers of notches. The index feed 
is effected by means of a "Geneve "stop movement; but abso- 
lute correct indexing is assured by the use of a positive cam- 
actuated locking device for the indexing arbor. 



456 



TOOL-MAKING AND 



In connection with the punch and die used in a machine of 
this type a spring stripper is used, so as to leave a clear space 
above the die ; making it easier to introduce a new disk, and at 
the same time provide for holding the disk under pressure when 
the notch is being punched. This, consequently, obviates the 
necessity of using a clamping plate over the centre of the disk. 





FIG. 536. 



FIG. 537. 



When disks of the polyphase motor type, having holes or 
notches punched in the inner periphery, are required to be 
notched in a machine of this type, it is necessary to do the 
notching before the large inner circle is removed, as its surface 
is needed for carrying the disks in notching. In such disks one 
or two small holes are previously punched in that portion of 
them that is afterward cut away, in order to serve as guides in 
the notching and centre -hole punching operations. 

The kind of disks which are of moderate diameter and most 
frequently required in large quantities are those used for street- 






FIG. 538. 



FIG. 539. 



FIG. 540. 



car motors. To produce them powerful power-presses are used. 
These presses are equipped with dies so constructed and arranged 
that the inside of the disk with its key-slot, and the outside with 
its notches, are cut simultaneously at one stroke, as shown in 



INTERCHANGEABLE MANUFACTURING. 



457 



Fig. 540. This method constitutes the quickest, most accurate, 
and economical way of manufacturing armature disks in large 
quantities. The presses in which such dies as are necessary for 
such work are used, are provided with knock-out attachments 
which discharge the scrap and the disks so that they lie loosely 
on top of the dies, thus allowing of their easy removal. 

In regard to the power-presses used for disk punching, it may 
be stated that the requirements of armatures for electric work 





FIG. 541. 



FIG. 5i2. 



have led to the construction of presses which differ in points 
from those used for other styles of sheet-metal working. As it 
is always essential to have the outside and inside exactly concen- 
tric, so that all notches in the disks shall coincide perfectly with 




FIG. 543. 

one another when assembled in " cores," it has been found best to 
adopt dies which, by being cut simultaneously, eliminate the 
inaccuracies which are wellnigh unavoidable when the cutting 
is done in two or more operations. In many cases, the notches 
and key -seats are also punched at the same time. To accom- 
plish these results in one operation, dies of great accuracy are 



458 



TOOL-MAKING AND 



required, which, in addition to the cutting parts, must be 
equipped with "knock-out" pads that will automatically deliver 
the punched disks and scrap from within the dies. The dies 
used in these methods of producing the disks are known as 
"compound dies," and are usually built up in sections which 
have been hardened, ground, and lapped to size. However, not 
infrequently, they are made in the usual manner, but the results 
are not so accurate. These compound dies are very expensive, 
costing all the way from $150 to $1,000 each. Fig. 543 shows 
plans of a compound punch and die. As a rule these compound 
dies are used in presses provided with upper and lower die 
knock-outs, thus obviating the necessity of the strippers in the 
dies. The die sections are located in a steel casting. The rings 
are of tool steel, carefully and accurately worked out, hardened 
and ground to size, while the remaining ones are left soft. The 
dark sections in the figure indicate the cutting parts. 

As the installation of the above-described method entails a 
great deal of expense and can be adopted economically only 
where disks are required in large, steady quantities, it is at once 
apparent that the dies would be too costly to use for producing 




FIG. 544. 

disks in small lots. For this reason another method is in vogue. 
This method consists of cutting out simultaneously the plain out- 
side and the hole, as shown in Fig. 536, and then punching the 
notches on a notching press. By this method a perfectly con- 
centric blank is produced ready to be notched. As by this 
method the outside notches are cut separately, the power of the 



INTERCHANGEABLE MANUFACTURING. 



459 



presses in which the work is done is equal to much larger diame- 
ters than those used in the method before described. 

ID. producing very large disks there is a great deal of scrap, 
but this scrap is prevented from going to waste altogether by 
being worked over into disks of smaller size. From the inside 
scrap, the projections corresponding to the key notches are re- 




FIG. 545. 

moved by forcing the disk through a circular trimming die which 
punches the centre hole at the same time, and thus no great 
waste of stock is entailed. 

In manufacturing armature segments in very large quantities 
the outside and the holes are usually cut simultaneously in dies 
in which the stripping of the scrap and the segments from them 
is entirely automatic, for both the upper and lower sections. A 
press specially designed and used for this class of work is shown, 




FIG. 546. 



equipped with proper tools, in Fig. 547. The cutting of sec- 
tions and segments complete with dovetails, and all notches and 
holes up to 35f inches long, can be done on a press of this sort. 
However, most segments of large size are first punched plain and 
the notching and perforating are done in succeeding operations. 



460 



TOOL-MAKING. 



When the plain segment blanks are not produced in dies, a 
circular shear of the same type as that used for disk cutting is 
used ; it being equipped with a segment-cutting attachment, as 
shown in Fig. 545. 

In Fig. 546 we have a side view of an armature-segment 
notching press. The segment-notching attachment on this ma- 
chine allows of handling segments having a radius of from 36 to 
96 inches and up to 36 inches in length. The manner in which 




FIG. 547. 



the segments are notched is as follows: The segment to be 
notched is clamped in a holder at the forward end of a long 
radius bar, and is traversed across the die face by means of an 
indexing mechanism and change gears similar to those on the 
regular disk notching press ; when the segment is notched all 
around the outside or inner edge as required, the press stops 
automatically. After the operator releases a hand lever the seg- 
ment may be returned to its original position and removed from 
the press. 



CHAPTER XXVIII. 

The Manufacture of Accurate Sheet-Metal Parts in 
the Sub-Press. 

THE SUB-PKESS. 

THE great increase in the manufacture of innumerable small 
machines of precision which are made up almost entirely of sheet - 
metal parts, together with the increasing demand for cheap but 




FIG. 548. 



accurate watches, clocks, time recorders, meters, cyclometers, 
and other articles, the utility of which depends entirely upon 
their precision, has created a demand for accurate presses, dies, 

461 



462 TOOL-MAKING AND 

feeding devices, and automatic arrangements with which to pro- 
duce sheet-metal parts in endless repetition with their complete 
interchaugeability assured. For the production of such parts, 
dies of great accuracy, together with feeding devices which are 
positive in action, and the sub-press are necessary. 

Sub-presses are distinctly different from the other machines 
which are used for the usual or ordinary lines of sheet-metal 
work, in that they are made so as to form component parts of 
the dies, and that they are used almost exclusively for the deli- 
cate dies which are required in the economic manufacture of 
parts of the kind used in the machines, devices, etc., enumerated 
above. 

UTILITY OF THE SUB-PRESS NOT GENERALLY 
UNDERSTOOD. 

Notwithstanding the extensive use to which the sub-press and 
its accurately made dies have been put, its use and the making 
of the dies for it are not understood by superintendents, fore- 
men, and tool-makers of sheet-metal goods establishments as they 
should be. Thus the more extensive use of these tools lias been 
interdicted. Were the case otherwise, and the utility of the sub- 
press and the making of its dies more generally understood, there 
would be less worry and more satisfaction in the accomplishment 
of results which, in many establishments, are at present being 
attained by means which are now obsolete. In view of this state 
of affairs I feel that complete descriptions of the sub-press, and 
how to use it and its dies, will be of great value to all engaged 
in the manufacture of accurate sheet-metal parts, articles, or 
devices. 

PRINCIPAL USE OF THE SUB-PRESS. 

The principal use to which the sub-press is put, is for the 
manufacture of sheet-metal parts which, because of their unusual 
accuracy, have to be produced in dies which cut the outside and 
the inside, as well as any perforations, simultaneously, or at least 
within the one compound die. By the use of the sub-press and 
its accurate dies the finest work may be accomplished with ease, 



INTERCHANGEABLE MANUFACTURING. 463 

as the dies may always be kept finely adjusted for the work; 
while the enlinement will be perfect, and thus the possibility of 
shearing will be entirely eliminated. 

COST VS. LONGEVITY OF THE SUB-PEESS. 

In regard to the cost of a sub-press and a pair of dies for pro- 
ducing an intricate sheet-metal part, the first outlay is consider- 
able ; but then this is really all the cost, as the construction of 
the press is such that no damage can be done to it while it is 
being set up or run in the power-press ; while the dies for it 
require but little repairs outside of an occasional grinding of the 
faces. When it is stated that from 50,000 to 100,000 perfectly 
interchangeable blanks may be cut and pierced in a sub-press 
without grinding the punch and die faces, the accuracy and long- 
evity of the tools may be imagined. 

HOW TO CO:N T STEUCT A SUB-PEESS. 

In order to be able to construct a sub -press or a set of dies 
for it the tool-maker must be both skilled and accurate, and must 
use great judgment ; possessing these qualities he may, by care- 
fully digesting the following described methods, be sure of suc- 
cess. 

Fig. 548 shows in vertical section and Fig. 549 in plan, a 
sub-press such as is used in all watch, meter, and cyclometer 
factories. The sub-press consists of the stand 1, the plunger 2, 
the base 3, the nut 4, to tighten the babbit lining, and the hook 
nut 5, which connects the power-press plunger with the plunger 
2 of the sub-press. The stand 1 is the first part machined. It 
is faced and bored on the bottom, and then the barrel is faced 
and recessed to suit a flange by means of which the plunger 2 is 
centred at one end for babbitting. The stand is then ready to 
be drilled and tapped for the fillister head-screws, by means of 
which it is fastened to the base. These screws are also used 
to fasten the stand to a special lathe-chuck, by means of which 
it is bored 3 degrees, taper-faced on the other end, and then 
turned for the adjusting nut, but not threaded until the stand 
has been babbitted. The stand having been bored it is then set 



464 



TOOL-MAKING AND 



up in the shaper or keysetter, and four grooves are planed in the 
inside, parallel with the taper, to prevent the babbitt lining from 
turning. 

We now rough-turn the plunger 2, back-rest it, and then bore 
it for the punch piston ; after which it can be threaded for the 

nut 5. This nut should be made 
of machinery steel, and have two 
flats milled on it at o o, so as to 
be able to remove it from the 
plunger. "With this nut well 
screwed down the plunger should 
be turned to within about .005 
inch of the finish size, and then 
finished by grinding, making sure 
to have it perfectly parallel; 
after which it should be placed in 
the miller vice, and four grooves 
milled in it, being sure to have 
the miller vice exactly in line ; if 
the vice is slightly "out" a twist- 
ing motion will occur in the 
plunger when in operation in the 
press, and this will, of course, 
spoil the dies. Now we draw-file, 
the plunger, using No. 2 emery 
stick, which will give better re- 
sults than a file, and then all is 
ready for the babbitting. We 
get the babbit at the right heat, 
pour it, and allow it to rise 
about -J inch above the top of the 
stand. 

As soon as the stand has cooled enough to handle, the plun- 
ger should be forced down far enough to allow the babbitt to be 
faced and squared off on the end, and the thread cut on the end 
of the stand or nut 4. Now remove the plunger from the stand, 
and locate the stand in the lathe again; then cut a spiral oil 
groove of about 1-inch pitch in the babbitt lining. The stand 




FIG. 549. 



INTERCHANGEABLE MANUFACTURING. 



465 



and plunger should now be secured in the power-press, and 
pumped, using plenty of oil, and tightening down the nut occa- 
sionally so as to get a good bearing. It must be watched at this 
stage, in order that excessive friction may not heat the babbitt 
lining sufficient to cause it to swell, and thus destroy the stand. 
Now reface the stand in the lathe, and face the bottom and bore 
the seat about 2 degrees taper to fit over the taper boss on the 




base. The plunger may now be removed from the stand, back- 
rested, and recessed for the dies. The base can then be located 
on the face-plate of a lathe having previously planed the bot- 
tom and the boss turned 3 degrees, taper to suit the stand ; also 
recess it for the dies and lower stripper, after which it can be 
drilled and counter-bored, and then doweled to secure the per- 
fect alignment of the two sections. 



SETTING AND WOEKING A SUB-PEESS. 

The sub-press can be worked in almost any power-press of 
suitable space. However, usually, a special press is used for the 
purpose, as a short stroke and a stiff arch -framed press best meet 
the requirements ; Fig. 549 shows a press of this kind. 

To set a sub-press, simply slip it into place, as shown in Fig. 
549, by sliding the steel neck of the plunger into the press-slide 
hook, and theu locate the hold-drawn clamps into their places 
and tighten the screws or nuts, thus fastening the sub-press 

firmly to the bed of the power-press or bolster plate. The dies 
30 



466 TOOL-MAKING AND 

may now be set aiid all is ready to proceed with the punching. 
The changing of a sub-press is very quickly done, as no special 
skill is required. There are several different styles of sub-press 
frames; the most common is the round barred-arch shape. An 
overhang pattern is often used. For the very largest work, 
such as clock or time-register frame backs, a four-pillar sub- 
press, which cuts quite large blanks from stock as thick as 
T 3 inch, is used. The manner in which the punching in a sub- 
press is done must not be confounded with ordinary punching, 
as it is done in a different manner. As a rule three or more 
operations are performed at one stroke of the press that is, cut- 
ting the outside, cutting the centre, perforating the blank, and 
lettering it all at once. The stock to be punched is securely 
held between the stripper plates and pads ; thus the die is com- 
pound; thus the metal is straightened and held perfectly flat 
while being worked upon, and each and every piece produced is 
an exact counterpart of the one previously cut. 

ACTION OF THE DIES FEEDING OF THE METAL. 

In the production of the most accurate classes of work in the 
sub-press, the punch does not enter the die proper, but descends 
within a shade of its face, thus parting the blank from the stock, 
and 110 more ; the strippers flatten its edges out square. It must 
be understood, though, that the die and punch faces must be 
perfectly flat and without any shear in order for the work to be 
produced accurately ; for this reason a stiff, well-made press is 
required. Because of constructing the dies in this manner their 
longevity is greatly extended, as the punches merely pass through 
the comparatively soft stock and not in and out of the hardened 
dies, which would shear and wear them quite rapidly. Never, 
under any circumstances, allow the punches to enter the dies, as 
this will spoil the tools in a short time. 

As the sub-press is a small, convenient machine in itself, 
with its dies and punches always in perfect alignment, with no 
possibility of fitting out of order, it is always set ready for work 
and all chances of bad or inaccurate work are eliminated. While 
the first cost of this little machine is large, in the long run it is 



INTERCHANGEABLE MANUFACTURING. 467 

the cheapest die that can be devised for the accurate and rapid 
production of perfectly interchangeable sheet-metal parts. It is 
this little tool that has made possible the manufacture of the 
"dollar watch. 7 ' 

Roll feeds, or other automatic feeding appliances, are often 
added to the presses in which these sub -press tools are used. As 
the articles cut are forced back into their place in the stock from 
which they were punched by the strippers in the dies, the meta. 
stock is kept straight and it is punched and accurately fed along 
under the dies at a very high speed, from 75 to 130 pimchings 
per minute being produced. 



CHAPTER XXIX. 

Engraving, Sinking, Constructing, and Using Dies 
for Medals, Jewelry, Coins, and Art Goods. 

WOKKMAN VS. AETIST. 

THE cutting and engraving of steel dies for the embossing of 
medals, jewelry, and fine sheet-metal work is an art by itself an 
art which, besides requiring mechanical skill and a knowledge 
of the use of metal-working tools, requires a natural talent for 
that kind of work and the possession of that artistic ability that 
comes from the love of things beautiful. Without that ability 
the die-sinker is merely a workman, and will be incapable of 
originality : it is the talent that makes the artist. However, to 
those who are already skilled in the art of die-making and who 
possess to a certain extent the ability to duplicate designs, this 
chapter will prove greatly instructive ; while to those less gen- 
erously endowed the information contained herein will help them 
to progress further. 

ENGRAVING A HOB FOE SINKING A ' MEDAL DIE. 

In making the dies for medals, etc., the most app roved prac- 
tice is as follows: Taking a blank ready to be cut, Fig. 551, we 
grind the face dead smooth and then either copper it with a solu- 
tion of sulphate of copper or give it a thin coat of zinc white 
and allow it to dry. We sketch the medallion portion on this 
surface, as in Fig. 552, and cut away to the necessary depth all 
the outer sections until a perfect silhouette of the figure is ex- 
posed, as in Fig. 553. After this the coarser details are cut in, 
using small chisels, riffles, and gravers, and boldly rounding all 
portions which are to appear thus, as shown in Fig. 554. The 
last and most particular part of the work is to engrave and chase 
in the fine artistic details until the Avork appears finished, as in 

468 



INTERCHANGEABLE MANUFACTURING. 469 

Fig. 555. The " hob " for sinking the die for the face of the 
medal is thus made. 

MAKING DIES FOE EMBOSSING JEWELEY. 

In the making of dies for the embossing of jewelry the usual 
practice consists of working out the sample first to the shape re- 
quired, after which it should be soldered to the end of the piece 
of steel which is to form the punch. These pieces of steel are 
usually kept on hand and are turned to 1-J inches diameter and 






FIG. 551. FIG. 552. FIG. 553. 





FIG. 554. FIG. 555. 

are about 5 inches long, with the small end bevelled to a size just 
large enough to cover the sample. After the sample has been 
soldered to the end of the punch blank the outline of the templet 
is carefully and accurately worked out on the end of the punch 
by the best means available ; the bench miller will prove the best 
means to adopt for doing this part of the work. Carry out the 
outline to a distance of about -f% inch from the face of the 
punch ; then take the punch to the shaper and carry the shape up 
the length of the punch ; tapering it to run out about 1^ inches 
from the face. After this carefully file and finish all points 
round, so that the end of the punch will have the perfect outline 
of the sample. The sample may now be removed and the face 
of the punch shaped as the finished article is to appear. 

This shaping requires a little exercise of the artist's talent, 
but it is not very difficult if gone at with a little thought and 
system. The systematic method would be to coat the end of the 
punch with copperas solution, and scribe a line completely 



470 TOOT^-MAKING AND 

around the punch a distance from the end face equal to the thick- 
ness of the finished article. 

The dies are usually made of round annealed stock, turned 
to 1^ inches diameter, the ends faced to about % inch thick, and 
the face into which the impression is to be struck finished to 
a very high polish. Not the slightest scratch is permissible 
upon the face of either punch or die. This being done, take the 
punch which we will now call " master " punch and the die 
blank, to either a screw-press or drop-press, set both in. their 
respective places, and when all is in readiness, carefully clean 
both and oil very slightly with oily fingers. All being firmly 
fixed in position, the impression is now made. If a screw-press 
is used a few strong blows will be necessary, and if a drop -press 
estimate about the proper height from which to drop the weight 
with the surface to annealed piece, which will soon teach one 
about how much is necessary to strike a given depth. Raise the 
weight and let fall, catching the weight before a second blow can 
be struck. The result of this will be a clean-cut impression, with 
the original polish of surface almost perfectly preserved but car- 
ried down into the blank. Of course the metal will be thrown 
up around the impression, and this can be faced off in either a 
lathe or a shaper, since it is necessary to strike a little deeper 
than required because of the edges being rounded. The die is 
now marked, etc., and hardened, using something to insure its 
coming out of this process clean, and then the impression is pol- 
ished out. It is very necessary for work of this kind that the 
dies, etc., be highly polished, and especially so when working 
gold-filled stock, for the smoother the work comes from these 
dies, the less buffing will be necessary to bring it to a finish. 

For the high finish, either Vienna lime or fulminate of iron 
will give excellent results. Chuck a round stick orange wood 
in a speed-lathe or drill-press. Shape the end with a file 
while running, and use either of these preparations with water. 
The Vienna lime is cleaner, fulminate of iron gives the most sat- 
isfactory results. We now have a die ready for business, and 
when this becomes worn large from use, which it surely will do 
in time, another die can be struck from our master punch. 

After a punch has been found to give the results sought for, 



INTERCHANGEABLE MANUFACTURING. 471 

it is a very good plan to strike off several dies at one time, 
especially if manufacturing anything like this in large quanti- 
ties, as there is a gritty surface to annealed pieces which will 
soon wear out a die, and the form of the piece being changed, 
will, in a greater or lesser degree, affect subsequent operations. 
It is a good plan also to strike off one die deeper than is in regu- 
lar use, finish, and reserve as a master die. This would then 
make it possible to reproduce the punch also if by accident or 
otherwise it became damaged or lost. 

To produce a punch from the master die we must, of course, 
use an annealed blank turned up as before and shaped to the 
impression in the die. This can well be done by laying out the 
outlines on the end of the punch blank, shape it accordingly in 
the bench miller, and file it to about the desired shape. Place 
the master die and punch blank into the die, though not hard. 
Now remove the punch and ease off all spots showing contact. 
Eeplace punch blank and repeat until nearly the exact form has 
been taken, then ease off the sides slightly, polish highly, and 
return to the press for a finishing blow. The object of this is to 
work the punch nearly to shape, and to fit the die so that in the 
finishing blow the first contact will be in the bottom of the im- 
pression. The metal seems to flow into the die better where con- 
tact is at first, and should there be a scratch or other sharp 
indentation, it cannot be rounded out. It is also interesting to 
note that if a drop of oil gets pocketed in the bottom, this oil 
will prevent the die being filled out, no matter what pressure is 
exerted, so that the rule seems to be for either the punch or the 
die : "Let there be no scratches or dents in either surface ; polish 
highly; keep the surfaces clean from grit, etc., and oiled but 
slightly with slightly oiled fingers, and rubbed on at that." 
Finish the taper part of the punch in the shaper and vice, as 
already explained. Polish, harden, and finish as usual. 

Quite contrary to what might be expected by many, sinking 
small dies in this manner does not induce strains sufficient to be 
of any serious consequence, and I dare say that with annealed 
steel there is no more chance of loss than by the method of first 
heating before striking the impression. In fact, an experienced 
man almost never loses a die. 



472 TOOL-MAKING AND 

When not in use the master punch and master die should be 
coated with vaseline and stored away in a vault or other safe 
place. If preferred, these tools can be packed in powdered lime, 
same as polished spring wire is packed, to preserve the polish. 

CHASING THIMBLE, CANE, WHIP, AND UMBEELLA 

MOUNTINGS. 

The small indentations on the end of a thimble, cane, whip, 
and umbrella mountings, are embossed with kuuel wheels where 
the design will permit. Very fine work is hand-chased, which 
is performed by filling the articles with lead and afterward driv- 
ing the thin metal into the lead with chasing tools, the latter 
being a small, blunt chisel of proper shape to fit the designs or 
ornaments wanted. 

MODELING INTEICATE DIE PATTEENS. 

The modeling of intricate die patterns is accomplished in 
different ways, according to the nature of the work : carving in 
wood, moulding in plaster, moulding from " modeller's wax," 
or moulding in gelatin. The once most common method, but 
now wellnigh obsolete, was that of carving in wood. For large, 
bold designs the plaster cast is the best. First a rough outline 
of the work is formed from freshly mixed plaster. After this 
has set it is cut or carved into the desired form by keeping it 
moist and using sharp wooden or brass tools ; steel tools will not 
do, as they rust rapidly. In some cases modellers make their 
first model of clay, then make a plaster or gelatin mould from 
this by casting ; and lastly a reproduction of the original model 
from this cast. 

GELATIN MOULDS. 

When a clay model has been made and it is designed to repro- 
duce in gelatin, soak the best white glue in cold water for 
twenty-four hours, drain off all the water, and melt the soaked 
glue in a water- jacketed kettle, bringing it to the thickness which 
will give it the consistency of soft-rubber when cold. To pre- 
vent the gelatin from sticking, moisten the model with a mixt- 



INTERCHANGEABLE MANUFACTURING. 473 

ure of common soap and lard oil. Pour the glue upon the 
model, the latter being incased in a lead or board box ; allow the 
mould to cool for about twelve hours, and then separate the cast 
from the model by gently rapping around the edges of it. If 
the model has two surfaces from which casts are to be made, a 
thread should be attached to the back and extended out of the 
mould at both ends, so that it may be used for cutting open the 
mould and removing the model after the mould has cooled. 

Another good recipe for a gelatin mould is the following: 
Dissolve 20 parts of fine gelatin in 100 parts of hot water, and 
add one-half part of tannin and the same amount of rock candy. 
A mould made of glue or gelatin only will become more durable 
if a solution of bichromate of potash and water is poured over it 
and the mould afterward exposed to the sun. Use one part of 
bichromate to ten parts of water. Always remember to oil all 
models before covering them with glue or gelatin, otherwise you 
will fail to secure a good mould and may warp the model. 

USE OF "MODELLEB'S WAX." 

To make impressions of dies in which the designs are very 
elaborate, or composed of very fine lines and curves, use " mod- 
eller's wax." To make this wax, take two parts of beeswax to 
one part of bayberry wax ; dissolve and mix well and then spread 
it over the face of the die while warm, first moistening the face 
of the die with strong soap water to prevent sticking. To secure 
an impression of a large, bold design, use " dentist's plaster," 
mixing it with water until about as thick as molasses. It will 
be necessary to work fast, as the plaster will set quickly. Wipe 
the face of the die with lard oil and common soap solution and 
then spread the plaster over the die, running it from end to end. 
After the plaster has set, heat the die slightly and lay it aside 
for about twenty minutes, after which rap the edges of the die 
until the impression separates from it. In pouring the plaster, 
allowing it to flow from side to side will prevent the formation 
of air bubbles in the depressions. The further exclusion of air 
may be ensured by paddling or churning the plaster. As plaster 
shrinks considerably in drying, it will be necessary to remove the 
cast from the model as soon as it becomes dry. 



474 TOOL-MAKING AND 

As a rule, 110 matter how carefully plaster casting is done, 
some defects will appear in the casts, which will have to be 
patched. Wait until they are thoroughly dry and cold and then 
scrape the damaged surfaces before patching. 

DIES FOR FORMING LARGE ORNAMENTAL 
ARTICLES. 

The dies used for bending and forming large ornamental arti- 
cles of sheet metal are usually cast iron. Very little work is 
done on such dies, as they are cast from a carefully prepared 
model, a fac-simile of the article to be formed, using it as a pat- 
tern and working out the die surfaces in a manner similar to the 
moulding of a pattern in sand. Drop dies are often made in 
this way, and from these steel dies are dropped, producing them 
to almost the correct finished shape, thus dispensing with con- 
siderable difficult filing, chipping, and graving. 

WATER, OR FLUID -DIES. 

All kinds of hollow ware, such as lamp bodies, artistic toilet 
cases, match safes such as shown in Fig. 556, silver and Britan- 
nia ware and ornamental soft brass shapes, are produced in 




almost exact reproductions of chased work by means of the 
"water die/ 7 of the type shown in Fig. 557. The " die" con- 
sists of a hinged mould having the desired decorations cut on the 
inside. These moulds are usually cast from carefully carved 
models and are then finished and touched up until all fine details 



INTERCHANGEABLE MANUFACTURING. 475 

are sharp and distinct. A special close-grained cast iron is nec- 
essary for such moulds. In use, the mould or "die" is placed 
under the press and the shell to be swelled and decorated is filled 
with water and enclosed within it. A plunger fitted to the ram 
of the press, and fitting the opening in the top of the mould 
tightly, descends and causes the confined fluid to swell out the 
metal into the designs in the mould. This is a very economic 



Plunger 

Knurled Sleeve 




Shell 



way of producing decorated hollow ware, and is used almost to 
the exclusion of all other methods in the large silverware estab- 
lishments. To produce very plain figures, swells and shapes in 
soft metals, a piece of soft-rubber is used as a swelling agent, 
the plunger compressing it on the descent. 

COMBINATION DIES FOE EMBOSSED WOEK. 

Flat, stamped, embossed, or raised sheet-metal articles are 
usually drawn and stamped up in a first operation and trimmed 
afterward in a plain trimming-die. Sometimes, when the de- 
signs are simple or shallow, the articles are produced in one 
operation in a combination drawing and embossing die. This is 
not done as a rule, as the metal is apt to draw and form un- 
equally, and thus the finding of a blank which will draw up per- 
fectly without fins or rough edges is very difficult. Again, the 
two operations are combined in a progressive die, in which the 
metal is first stamped and drawn, or vice versa, and then fed 
along and trimmed or blanked out. 



476 TOOL-MAKING AND 

MAKING "HOBS" AND SINKING EMBOSSING DIES. 

In the making of embossing dies several methods are in 
vogue. Sometimes both dies are made of steel, or one of steel 
and one of copper or brass, or one of hard bronze and one of 
soft brass, while for very large work of bold designs one die is 
made of cast iron and the other of brass. 

In making steel dies for striking up gold, silver, and other 
valuable metals the first operation consists in carefully anneal- 
ing the blank which is to form the master die or "hob," and then 
getting a dead smooth finish on the face, which is then cut and 
engraved and cut until an exact reproduction of the required de- 
sign is raised on it. Careful engraving and scraping and giving 
the proper amount of draft and radius to certain points will be 
necessary in order to obviate the tendency of the metal to cut 
apart while being worked; this will be most likely to occur 
where perpendicular lines or surfaces are presented. After hav- 
ing finished and polished all portions of the design the u hob" 
may be hardened and drawn to a deep straw temper. We now 
have a master die or "hob" with which to sink the other die. 
This "hob " is fitted to the ram of the press or of the drop ham- 
mer, whichever it is to be used in. 

We now secure another annealed blank, and carefully finish 
the top and bottom. The master die is secured in the press ram 
and the blank is placed directly under it. Both faces of the dies 
are oiled and the master die is forced into the soft face of the 
blank until a perfect impression of every detail and line in the 
master die appears. This will require much time and patience, 
it being necessary to remove the blank several times and cut 
away the surplus metal thrown up. After the necessary amount 
of clearance has been given the sunken die, and all points ,are 
polished, it can be trimmed, faced and hardened, and tempered. 
From this die a brass, bronze, or copper "force" is then struck 
up, which is used in place of the master die in the production of 
the articles desired. If many dies of the" same kind are to be 
made, such as for coins, a number of sets are sunk from the mas- 
ter die, which is kept for that purpose alone; thus the exact 
duplication of the design is assured in all the dies. For coins, 



INTERCHANGEABLE MANUFACTURING. 477 

of course, both dies are of steel. In coin dies the date, which 
changes from year to year, is stamped in by hand after the im- 
pression of the master die or "hob" has been struck. 

In using a master die for making impressions the surfaces of 
the "hob " and the blank should be kept well oiled and the press 
should be turned very slowly by hand. By keeping the master 
die for making impressions only, exact duplicates of the worn- 
out dies may be produced, this being not possible by any other 
method, as no engraver can exactly duplicate his work by hand. 

When making very large steel dies by the method described 
above it will be found necessary to drop the blank hot. Heat 
the blank to a cherry red, drop the master die, remove the blank, 
remove the scale, trim and work out the surplus stock, and then 
re-drop cold. A perfect impression will be produced in this 
manner. 

BBONZE, BBASS, A^D COPPER DIES. 

The making of bronze, brass, or copper dies for embossing 
thin, soft sheet metal in shallow designs and shapes is usually 
accomplished by first casting from wooden or modelled patterns, 
and then taking a plaster cast of this, from which a mould or 
matrix is secured which is carefully scraped and polished. This 
matrix should be of hard brass or bronze, and the mould of much 
softer metal, so that it may be forced or dropped into it until a 
perfect impression appears. It will be found in dies of this kind 
that the surfaces will wear surprisingly long, as they become 
hard and tough through the dropping process. 

It must always be remembered that in all kinds of engraved 
dies a feature of great importance in their making is the neces- 
sity of cutting deeper all depressions and fissures, so as to leave 
all the higher portions in a position to be perfectly smooth and 
polished. This is to prevent the marring or splitting of the em- 
bossed side of the article. 

For the production of ornamental tinware and other articles 
in which the ornamentation is coarse and bold, cast-iron dies and 
brass or hard babbitt moulds are used. These dies require little 
labor or skill to produce, as the plaster casts or moulds for the 
dies can be relieved in all deep places, and thus it is not neces- 
sary to rout out the brass mould afterward. 



478 TOOL-MAKING. 

When the article required to be embossed is very deep, or 
where the designs and ornamentation are much raised, it will be 
necessary to accomplish the embossing with two sets of dies. 
One set the first will have to be supplied with blank-holders 
and a die having a rough outline of the required design. In this 
die the metal will be drawn from between the blank-holders and 
into the die, and a crude impression of the required design will 
be given it. The article should then be annealed and struck up 
perfectly in a finishing die. Xot infrequently it will be found 
necessary to use three, or even four, sets of dies to accomplish 
the desired results in articles which are excessively deep. Trays, 
salvers, picture frames and plates having ornamental borders not 
too close to their edges, or circular articles with central raised 
designs, can be blanked out and stamped or embossed in a com- 
bination die in a single -action press, the die being equipped with 
a spring buffer and a blank-holder ring, or in a double-action die 
in a double-action press. Shallow shells, boxes or covers, either 
circular or rectangular in shape, can be blanked, drawn, formed, 
and embossed or panelled in a triple-action die in a double-action 
press equipped with an automatic lower punch slide. 

To fit the shanks of the embossing dies, upper and lower, or 
to turn the outsides, clamp the punch or "force "and die to- 
gether, and then machine as if one piece ; thus the perfect align- 
ment of the embossing faces with each other when the die is in 
use will be assured. 

Although for years spoons, forks, and embossed metal handles 
were produced under the drop hammer, this method has now be- 
come almost obsolete, as the improvements in heavy automatic 
presses and feeding devices for such has made their use for the 
production of such articles quite general. These machines pro- 
duce more and better work with less wear on the dies than the 
drop hammer. 



CHAPTER XXX. 

The Modern Art of Swaging, Swaging Machines, and 
the Cold Swaging Process. 

THE HAMMER. 

MAN'S first tool in shaping metal was the hammer, and with 
the advancement in appliances, during the centuries, the ham- 
mer has continued to hold its place. In modern metal working 




FIG. 558. 



FIG. 559. 



the hammer is supreme. Its form, it is true, is changed from 
time to time, but whether the hand fool or the power-driven 
hammer is considered, the principles underlying its use are still 
the same. 

The simplicity and effectiveness of the hammer have never 
been excelled in any other tool, nor even equalled. Whether 
metal be worked hot or cold, the hammer is the king of tools. 
Not only does the hammer produce a vast amount of work with 
a small expenditure of force, but it gives to the metal qualities 
which can be obtained in no other way. Strength, rigidity, 

479 



480 TOOL-MAKING AND 

solidity, and increased elasticity are all gained under the ham- 
mer, while in the cases of iron and steel a surface hardness is 
secured which cannot be produced in any other manner. 

SWAGING AND HAMMEBING. 

Swaging, however performed, is only a kind of hammering. 
The early smiths, it may be supposed, in the very infancy of the 
race certainly long before the dawn of history observed in 
working the metals with which they were acquainted, that the 
face of the hammer always left its impression when a blow was 




FIG. 560. Pointing for Drawing. 

struck. Any irregularity in the face of the hammer left a cor- 
responding mark on the metal struck. To this fact, undoubt- 
edly, does modern metal working owe both the art of swaging 
and the art of die sinking, drop forging, and embossing, for the 
fundamental principle in each is that of making a special face 
for the hammer and another for the anvil. 

These special faces for the hammer and the anvil are given 
the form which it is desired to impress upon the metal, which is 
to be struck between them. If the piece of metal which is to be 
worked is, for example, cylindrical in form, the face of each, 
the hammer and the anvil, is hollowed out, the depression being 
given the required shape or design. The metal worked between 
them is then forced by the blows applied into the hollows of the 
two faces, thus taking on the desired shape. 

While it may be supposed that the first swaging, crude though 
it must have been, Avas performed between a hammer with a de- 
pression in its face and an anvil with a corresponding indenta- 
tion, it is probable that it was not very long before the early 
smiths recognized the further fact that a great gain would be 
made in such work by separating the special faces from the ham- 
mer and the anvil, respectively. The hammer, therefore, was 



INTERCHANGEABLE MANUFACTURING. 481 

again made smooth and heated to be struck against a special piece 
of metal or false face, to which one-half of the required form 
had been given. The anvil, instead of being hollowed out ac- 
cording to the design of swaging to be done, was made a large 
solid block; heavy enough to resist the hardest blows, and pro- 
vided with means to receive and hold a second special face, the 
counterpart of that against which the hammer would be struck. 
What are now known as swaging tools or dies resulted. All that 
has been accomplished since has related to means of holding tools 
to be operated, to means of imparting the necessary blows, and 
to methods of controlling and guiding the work. In the follow- 
ing the matter is. a compilation from information kindly fur- 
nished the author by the Excelsior Needle Company, of Tor- 
riugtou, Conn., manufacturer of the Dayton swaging machine, 
and the technical journal Machinery. 

Strange to say, the ordinary dictionaries, in defining " swage" 
in the sense of a swaging tool, take into account only one of a 
pair as commonly used and as above described. One definition, 
for example, is as follows : " A tool having face of a given shape, 
the counterpart of which is imparted to the object against which 
it is forcibly impressed. When used ... it is either placed 
on the anvil so as to impress the metal which is laid thereon 
and struck by the hammer, or the work being laid on the an- 
vil the face of the swage is held upon it and the back of the 
swage receives the blow." But modern processes of swaging, 
work the metal on both sides or all around, as in the case of 
a rod or tube, and for this purpose employ both top and bot- 
tom tools. 

The use of false faces to the hammer and the anvil, as above 
set forth, or the use of swaging tools, as the corrected definition 
describes them, and which are most commonly called "dies," 
enables a number of blows to be struck in obtaining the required 
result, which secures an important economy of force, while also 
rendering the operation less trying to the metal. There is like- 
wise an important gain in the quality of the product. Further, 
the employment of dies makes possible the use of a machine for 
imparting the blows, in a way to secure rapidity of action and 

absolute uniformity of work. The force of the hammer is trans- 
31 



482 TOOL-MAKING AND 

mitted through the movable faces or dies without appreciable 
loss; in fact, with a positive gain in various points of effective- 
ness. 

THE COLD-SWAGIXG PBOCESS. 

The swaging process, although extensively used in^ certain 
classes of work, is, as a machine shop operation, very little if at 
all recognized. The success, however, with which this process 
is employed for certain purposes would seem to indicate that its 
use might be applied with profit to a great class of work that is 
at present performed either by hot forging or by machining. 

Cold swaging is the act of reducing or forming steel or other 
material while cold, such as drawing to a point or reducing the 
diameter of the work. This is performed by a machine which 
causes the work to be struck a great number of successive blows 
by a pair of dies of suitable shape to give the required reduction. 
The process is mainly applied to reducing wires, rods, and tubes, 
and is the only process by which rolled or plated stock can be 
reduced without destroying the plating or coating. For this rea- 
son it is largely used for jewellers' work, such as forming spec- 
tacle templets, fancy pins, and similar pieces. It is also exten- 
sively used for pointing rods or tubes which are to be drawn. 
It will put the best point known to wire drawers, on a rod or 
piece of wire in a fraction of the time that would be required by 
any other method, and the same applies to its use on tubing. 
The millions of needles, bicycle spokes, button hooks, crochet 
needles, etc., which are turned out annually serve to show some 
of the possibilities of the swaging process. 

The possibilities of the swaging process are almost without 
limit. The blacksmith through the ages has invented unnum- 
bered applications found in daily use, while the modern ma- 
chine builder has discovered various means of adapting swaging 
methods to the rapid and economical production of numerous 
shapes and forms required in the different trades and industries. 

Bod-making in steel and iron, as well as the kindred trade of 
making bars and axles, is essentially a swaging process. There 
are modifications in the details of the machinery adapting it to 
the purpose, but the principle is the same. In the same way the 



INTERCHANGE ABLE MANUFACTURING. 483 

tapering of tubes both large and small is better performed by 
swaging than by any other process. Modern swaging as a means 
of reduction supersedes rolling, grinding, milling, turning, and 




FIG. 561. 

drawing, for the reason that it improves the quality of the mate- 
rial and gives greater uniformity and better surface without 
waste of stock. 

One of a pair of tools or dies fastened in an anvil to hold the 
metal to be worked, and the other sustained above it and adapted 
to receive the blows of the hammer, constitutes one of the most 
useful forms of swaging-machines. Substitute for the hand 
hammer and its swinging blows a series of machine -driven ham- 
mers revolving around the pair of dies which are suitably held, 
and which deliver their blows in pairs upon the ends of the dies, 
thus forcing them together and against the metal that is between 
them, and a modern machine is produced the product of which 
excels in character and value anything that has ever preceded it. 



484 



TOOL-MAKING AND 



As an illustration of the saving of stock that may be accom- 
plished by the use of this process, we will consider a simple piece 
of rod which is tapered from full diameter to a small point, as 




FIGS. 562 and 563. 



shown in Figs. 562 and 563. In view of the piece marked A, the 
dotted lines show the original piece of stock from which it would 
be made if the work were done on a lathe or screw machine, by 




FIG. 504. 



the machining process, the dotted section showing the amount of 
material that would be wasted. In the lower view B, the dotted 



INTERCHANGEABLE MANUFACTURING. 485 

lines show the amount of stock that would be required to pro- 
duce it by the swaging process, and there would be no waste 
whatever. 

EOTAEY SWAGIXG-MACHINES. 

The rotary gwagiug-machine is now being made by a number 
of manufacturers, and while the details of the different machines 
vary in some respects, the principle is the same throughout. 
Eepresentative machines, made by swaging-machiue builders, 
are shown in Figs. 564 and 565. 

The principle of the modern rotary swaging-rnachine is shown 
iii the line drawing, Figs. 558 and 559. Inside of the head in which 
the spindle revolves is a set of hardened steel rollers B B B which 




FIG. 565. 



are fitted in recesses in the fixed casting, each of them being free 
to run on its own axis. The front end of the spindle A is large 
and has a slot across its face in which the hammer blocks slide. 
These have recesses in their inner ends for holding the dies d d, 



486 



TOOL-MAKING AND 



and in their outer ends are the rolls E E which are free to turn 
when they come in contact with those in the head. As the spin- 
dle revolves and the rolls in the die-blocks are brought into con- 
tact with those in the head, the dies are forced together on to the 
stock. After passing a set of rolls, the dies are thrown apart by 
the action of centrifugal force, which keeps them separate until 
the next set of rolls is encountered, when another blow results. 
The machines are run at a spindle-speed of from 400 to 500 revo- 
lutions per minute, and as there are eight rolls in the head, the 
result is from 3,200 to 4,000 blows of the die per minute. The 
work in these machines is not rested, as the rotation of the spin- 
dle distributes the blow evenly around the circumference of the 




Samples of Work Done with the Rotary Swaging Machine. ' 
1-2. Spectacle Temples (Steel) 7-8. Machine Neediest Steel) 

3. Fancy Pin (Rolled Stock) 9-10-11. Cotton Machine Spindles 

4. Ring Body (Plated Stock) (Hard Steel) 
5-6. Pin Tongues ( Steel ) 12. Bitt ( Steel) 

FIG. 566. 



piece being operated upon. In another type of machine the 
rollers are replaced by oscillating cams which, when they come 
in line with the ends of the die- block, form a powerful toggle- 
joint and bring the dies together with great screws which cause 
the wedges back of the cams to slide in toward the centre. 
Some samples of the work done with the rotary machines are 
shown in Fig. 566. 



INTERCHANGEABLE MANUFACTURING. 487 



THE DAYTON SW AGING-MACHINE. 

The "Dayton" swaging-machine, views of which are pre- 
sented in Figs. 567, 568, 569, and 570, employs dies which are as 
simple in their essential features as the most primitive swaging 
tools. These dies, which are adjustable in their relation one to 
the other, are carried in a slot in the face of a revolving mandrel, 
and are held between a pair of blocks with rounded ends. On 
the side of and around the mandrel is an annular rack containing 
loosely a number of hardened steel rollers. The revolution of 




FIG. 567. 



FIG. 5(18. 



the mandrel causes the dies and blocks with rounded ends to 
pass between successive pairs of opposing rollers which force 
the dies together. The mandrel is hollow to permit the work to 
be fed through it. The dies revolve rapidly around the work, 
which is stationary, while the rack containing the rollers revolves 
very slowly, being moved only by the slight motion of the rollers 
during the time of contact with the blocks. Accordingly, the 
effect of the dies is very evenly distributed about the work. 

The dies are blocks of hardened steel, which have formed 
upon their inner faces the impression of the shape or the diame- 
ter of the work it is desired to produce, with an enlargement or 
flare at the outer or entering end large enough to allow the unre- 
duced stock to enter. The dies are set up, or what is the same 
thing, the blocks with rounded ends, or the backs as they are 
called, are made to project more by placing thin plates of steel 
between the ends of the dies and the backers. The dies and 
backers are held in place in the slot in the face of the mandrel 
by suitable plates. 

Eef erring to the cuts, 'Fig. 567 shows a face view or front 



488 



TOOL-MAKING AND 



elevation, with plates removed, aiid Fig. 568 a longitudinal sec- 
tion of one of the smaller sizes of the Dayton swaging-machine. 
The working parts of the several sizes are essentially the same, 
so that a description of one will answer for all. 

Fig. 569 shows the roll rack, face view, cross-section (one- 
half), and side elevation (one-half). 

Fig. 570 shows the face of the mandrel with the slot for re- 
ceiving the dies and backers, also a sectional view indicating the 





FIG. 569. 

central aperture for receiving the work. There are also shown 
the dies B in both side and end views and backers C. The plate 
used for holding the dies in place is shown at D. 

Referring again to Fig. 568 it will be seen that the balance 
wheel, and fast and loose pulleys, are attached to the mandrel at 
the back, and that the mandrel carrying the dies revolves within 
the rollers R; also that the roll rack, held in place within the 
cavity of the head of the machine by the plate F, is free to re- 
volve as moved by the backers striking the rollers. The head of 
the machine, which is of cast metal, is reinforced by a wrought - 
iron ring, shrunk into it upon the outside, and by a hardened 
steel ring on the inside. 

The mandrel is adapted to be run at any rate of speed re- 
quired by the work being done. "With five pairs of rollers in 
the rack, as shown in Fig. 569, there will be ten closures of the 
dies to each revolution, varied only by the slight motion im- 
parted to the rack by the backers striking the rollers. Eunning 
at a speed of 400 revolutions per minute, therefore, the blows 
upon, or closure of, the dies will approximate 4,000. The effec- 
tiveness of the machine is thus made apparent. 



INTERCHANGEABLE MANUFACTURING. 489 



HOBIZOXTAL SWAGIN T G-MACHIKES. 

The horizontal swaging-machine was originally designed by 
Mr. John Henderson, of Waterbury, Conn., and the first ma- 
chines were built by him. Later, the manufacture was trans- 
ferred to the Waterbury Machine Company, by whom this type 
of machine is now manufactured. The horizontal is especially 
designed for work of a heavy nature, such as is encountered in 
mills where rods and tubing are manufactured. It is constructed 
on a principle entirely different from that of the rotary machine. 
Fig. 571 shows a machine of this type. The round hole at the 
left, in line with the upper bearing, is the opening where the work 
is introduced. The centre of this hole marks the place where the 
dies are split on the vertical line. One-half of the die is backed 
up directly against the heavy casting of the frame, and the other 
half, toward the bearing, has a reciprocating motion on the hori- 
zontal line. The means by which this motion is obtained will be 
seen by reference to Fig. 571. 

The lower main shaft A carries the balance wheel and has a 
crank of short throw between the bearings, while the upper shaft 
_B, of large diameter, has a crank with a throw about six times as 
great. A connection C joins these two cranks; it will turn the 




FIG. 571. 

upper shaft through but a portion of the circle. If a line be 
drawn through the centre of this upper shaft, so that it is hori- 
zontal when the shaft is in the middle portion of its turn, it will 
follow that this shaft will have a rocking motion about its cen- 
tre, and the diameterically opposite points where this line meets 
the periphery of the shaft on either side will each pass the centre 
twice for every revolution of the pulley. If, now, a system of 



490 TOOL-MAKING AND 

horizontal toggles be interposed between the reciprocating block 
and the frame casting at the right, in which system the middlle 
block passes through the shaft, it will follow that by the rocking 
motion of this block the distance between the extreme ends will 
increase and decrease twice per pulley revolution, or, in other 
words, the number of blows will be twice the speed of the pulley. 
A spring, not shown in the cut, is used to separate the dies be- 
tween the blows. 

These machines reduce up to 2f inches in diameter and tubes 
up to 4 inches, and the amount of reduction ranges from -J- to 
^ inch for rods and -J to % inch for tubes, depending upon the 
diameter and nature of the material. Where a much greater re- 
duction is required than can be made by passing the work once 
through the dies, it has proved a great convenience to use a ma- 
chine with three sets of dies which gradually decrease in size. 
This is brought about by lengthening the machine out at the left- 
hand end for two extra pairs of dies, and as but one pair is 
in use at a time, motion is transmitted from one set to the 
other, all having a sliding fit in the opening. The form of the 
die is a cube, so that four faces may be used as required, the 
dies being turned around to bring similar half -openings together. 
When small diameters are required, several sizes can be cut on 
each face, and the changing from one size to the other is but the 
work of a moment. 

While the machine is principally designed to point rods and 
tubes for subsequent drawing through dies, it has numerous 
other uses, such as flattening round stock to a desired shape with- 
out waste of material. In this way it has been successfully ap- 
plied to shaping ends of rods for screw-driver blades, the round 
rod being merely pushed into the opening and the finished article 
withdrawn without any fin or waste. Many other operations of 
a similar nature may be performed, and in this class of work it 
covers a ground not practicable with any other type of machine. 

SOME EFFECTS ON WOEK ACCOMPLISHED BY 
SWAGING. 

The work performed by the swaging process is done by press- 
ure rather than by blows. Accordingly, there is a flow and re- 



INTERCHANGEABLE MANUFACTURING. 491 

adjustment of the molecules of the swaged metal, the effect 
of which extends equally throughout the piece in a manner to 
strengthen it and add other desirable qualities. To perceive the 
adaptability of the machines to a very wide range of work, from 
articles of the smallest dimensions up to those of a considerable 
size, requires only an acquaintance with the principle upon 
which they operate. 



CHAPTER XXXI. 

PROCESSES AND METHODS FOR THE WORKING 
OF ALUMINUM. 

ALUMINUM VS. OTHER METALS. 

THE innumerable uses to which aluminum has been put dur- 
ing the last few years, and the large variety of articles from 
kitchen utensils to drop forgings now produced from its vari- 
ous alloys, promise that the " beautiful white metal" is destined 
to be very extensively employed. Sheet aluminum, at least, is 
replacing the other metals, as experiments have determined t hat- 
it can be worked as expeditiously and economically as the older 
commercial sheet metals. It can be worked, when of a proper 
alloy, as easily as sheet brass, German silver, or tin-plate, and in 
numerous instances when the tools have been made correctly 
and the metal is lubricated properly while working it can even 
be worked more cheaply than any of the other sheet metals. 

DIFFICULTIES ENCOUNTERED IN WORKING. 

The most serious difficulties to be encountered in working 
aluminum are "hookiug-in," clogging and squeaking, in drill- 
ing; tearing and "gouging-in," in milling and planing; " jam- 
ming" up or blocking of punchings in dies, and consequent 
breaking of punches; the cohesion of fine particles of aluminum, 
compressed hard, to the cutting-edges of punches and inside of 
dies, and on bending or forming dies scratching the aluminum; 
parting or breaking the metal in drawing it. 

PURE METAL VS. ALLOYS. 

One thing that a great many mechanics are not aware of is, 
that aluminum should hardly ever be used- in its pure state. 
Many of those who have experienced difficulties in working the 
metal have been using the pure metal instead of a suitable alloy. 

492 



INTERCHANGEABLE MANUFACTURING. 493 

A majority of the aluminum alloys compare with the pure metal 
about as brass compares with copper, and as brass can be worked 
more easily than pure copper so aluminum alloys can be worked 
more easily than pure aluminum. One has only to gaze at the 
variety of articles and novelties which may be found in a shop- 
window or on a department-store counter, and to note their 
cheapness, to understand that there can be no great difficulty in 
working the metal into any shape that any sheet metal will flow to. 

SECEETS IN THE WOEK1NG OF ALUMINUM. 

The two great secrets that is, if we may term them secrets 
in the working of aluminum, either in its pure state or in any of 
its alloys, is the use of a proper lubricant, and in the proper 
shape of the cutting-edges of the tools. 

GEADES AND ALLOYS OF SHEET ALUMINUM. 

There is a great variety of grades and alloys of sheet alumi- 
num on the market, so numerous that no difficulty should be ex- 
perienced in producing that suitable for any special purpose. 
Aluminum may be had in much the same variety as sheet brass, 
or in all degrees of hardness, from dead annealed stock to the 
pure, stiff, springy aluminum. Next to the pure metal is a hard 
grade of alloys, ranging from dead soft stock, which will spin, 
draw, or form up hard and stiff, to the same grade hard rolled. 
After that comes another set of alloys which are replacing sheet 
brass in a large variety of kitchen utensils, novelties, parts of 
instruments, mechanical appliances, and the lithographer's stone. 
Lastly there is another grade of alloys which has been perfected 
lately from which great things may be expected, which are begin- 
ning to be used for drop-forgings. Experiments have shown 
that drop-forging can be accomplished with this metal more 
easily and satisfactorily than with many others, because certain 
alloys of aluminum can be worked cold. 

WORKING THE METAL. 

Now about working the metal. In turning, milling, or drill- 
ing aluminum in its pure state more difficulty has been experi- 
enced than in the press- working of the sheet metal. All these 



494 TOOL-MAKING AND 

difficulties disappear if the tools are made properly and the right 
lubricant is used. The tool should be made with lots of top 
clearance and bottom rake, and instead of the stub point, as used 
for brass, it should be lengthened out. The top clearance 
should be sufficient to allow the turnings to free themselves 
easily and not clog around the point. Lastly the tool should be 
tempered at a light straw, and stoned to a keen edge. 

LUBKICAXTS TO USE. 

As to the best lubricants to use for the machine operations 
of turning, milling, or drilling, crude oil is best for milling and 
kerosene for drilling ; while for turning, soap water, and plenty 
of it, will give grand resuls. A few years ago a large number 
of small electric cloth-cutting machines were being built under 
my supervision, the motor cases, brackets, standards, and bases 
of which were castings of aluminum, all of which had to be ma- 
chined all over to interchange perfectly. A number of fixtures 
were constructed for their production, which were described and 
illustrated by the writer in a series of articles in the columns of 
the American Machinist during September and October, 1900, 
under the title of " Tools for Interchangeable Work." I had to 
do a great deal of experimenting to produce the parts to the re- 
quired degree of finish and interchaugeability. All sorts and 
shapes of cutting tools were tried and different lubricants were 
used. It was found that drills, counterbores, reamers, centres, 
and turning tools would work beautifully w^heu lots of clearance 
was given them, the edges being well hardened and then stoned 
to a keen edge; that soap water was the best lubricant for drill- 
ing, and for large counterboring a cheap grade of vaseline. 
With the crude oil for a lubricant in milling, butt mills, \ inch 
in diameter, were used to take deep, wide cuts without undue 
strain on the teeth, without the cuttings clogging; and, instead 
of a coarse, torn texture resulting, a shiny, smooth finish was 
the pleasant attainment. In one large shop in Brooklyn, which 
makes specialties of lithographing presses, bronze machines, and 
bronze lithographing dusting machines, they formerly used large 
numbers of brass brackets for the grippers on the presses, but 
now they use aluminum castings. 



INTERCHANGEABLE MANUFACTURING. 495 

CUTTING DIES FOB ALUMINUM. 

In cutting dies for aluminum there should be at least one de- 
gree clearance. If the blank is over -fa inch thick and a smooth, 
uniform edge and exact size of blank are required, it should be 
recut or " shaved " in a second die, which should be made straight 
011 the inside cutting edge for not more than the thickness of one 
block or two at the most in order that the die may retain its 
exact size after re-sharpening. Allow about 0.01 inch on the out- 
side of the blank for shaving to % inch of thickness, but if the 
blanks are of hard aluminum alloy, half that amount will be 
sufficient. 

The cutting-edges of both punch and die should be sharpened 
very smoothly after grinding with an oil stone. 

Lard oil or melted Eussian tallow, the best for lubrication, 
should be used on both sides of the metal. 

Punches and dies should be carefully cleaned occasionally of 
the fine particles of aluminum that will be found adhering to the 
edges. 

DBA WING-DIES FOR ALUMINUM. 

In drawing aluminum of a thickness not more than -^ inch 
and a depth of draw more than \ inch, to avoid the tearing or 
wrinkling of the blank it should be held between a ring sup- 
ported on pins and springs and the face of the punch, rather 
than between the edge of the forming cavity of the punch and 
the sides of the forming-block, as is the case in a draw-plate die ; 
but, however it may be held, after it is drawn up first in U -shape 
redrawing several times if necessary in ordinary draw-plates 
and plungers care must be taken not to employ too fast a speed 
in the operation, or the work will break at the bottom through 
too sudden impact. 

If the aluminum to be drawn is thicker than -J- 2 - inch, it can 
be drawn direct, without the spring ring mentioned above, to a 
depth of f inch, or even deeper, the exact depth depending 
largely of course upon the composition of the aluminum alloy, 
the shape of the article to be produced, the finish on the dies, 
and the speed of the press. 



496 TOOL-MAKING AND 

Aluminum is not a suitable metal to work in compound or 
sub -press pieces, as the number of pieces of this metal that can 
be punched out without putting the dies out of commission by 
clogging and consequent breaking of punches will not be suffi- 
cient to pay for the cost of the tools. 

DRAWING ALUMINUM SHELLS. 

For the drawing of aluminum shells, tools of the same con- 
struction as those which are used for the production of brass or 
tin ones should be used. One peculiarity of aluminum which 
manifests itself when drawing the metal is that one cannot ob- 
tain as great a depth with it in one operation as can be done 
with brass. This is because the tensile strength of aluminum is 
somewhat less than that of the other metal. It may, however, 
be drawn deeper without annealing than any other commercial 
metal. An article made of brass requiring, say, three or four 
operations to complete, must usually be annealed after each re- 
drawing operation ; conditions, such as the thickness of the stock, 
depth of draw, etc., determining this. With aluminum, how- 
ever, if the proper grade is used, it will often be found possible 
to perform the entire number of operations without annealing at 
all, or at most once. At the same time a finished shell will be 
produced which will be equal in every way to one made from 
sheet brass. 

BENDING AND FORMING DIES FOR ALUMINUM. 

Bending or forming dies for aluminum should have all the 
friction parts very smooth and polished in the direction of the 
draw or bend; that is, the grain of the die and punch should be 
in the direction in which the metal travels in the die. Lard oil 
should be used on both sides of the work. 

SPINNING ALUMINUM. 

In spinning aluminum, best results are obtained by employ- 
ing a high speed, with a light pressure of the spinning tool, 
evenly and gradually applied. Aluminum may be stamped 
under a drop-hammer with about the same weight and momen- 
tum as required for silver. 



INTERCHANGEABLE MANUFACTURING. 497 



ANNEALING ALUMINUM. 

Articles of aluminum may be easily annealed by heating in 
an ordinary muffle, taking care not to get the temperature too 
high. The proper annealing heat lies between 650 and 700 de- 
grees Fahr. The best test for the heat is to take a soft pine stick 
and draw it across the metal. When the wood chars and a black 
mark is left on the metal, it is sufficiently annealed and is in the 
proper condition to proceed with the further operations. 

POLISHING AND FINISHING ALUMINUM. 

Next to the working and machining of aluminum the most 
important processes lie in the polishing and finishing of it. 
After the articles have been produced, a fine polish can be given 
them by first using a rag buff treated with tripoli to cut down 
with. The high finish can then be attained by using a dry rouge 
that comes usually in lump form, first grinding it to as fine a 
powder as possible. The tripoli also should be very finely 
ground. 

For a great many manufactured aluminum articles a frosted 
surface is desirable. This is usually done by scratch -brushes made 
of brass crimped wire of, say, No. 31 to No. 34 B. & S. gauge. 
Three or four rows of bristles will do. To lessen the work of 
scratch -brushing, the metal may be first cut down with a por- 
poise-hide wheel and fine Connecticut sand, the sand being fed 
between the surface of the wheel and the article. By using this 
latter method first, the skin, pimples, and all surface irregularities 
are removed, and the scratch -brushing is made easy. When the 
worked metal is smooth and of good appearance the cutting 
down with tripoli will be all that is necessary, after which the 
rouge may be used as described, and the finished surface put on 
with the scratch-brush. By taking the preliminary precautions 
the scratch-brushing will frost the metal quickly and uniformly. 

Another way of obtaining a similar effect to that of the 
scratch-brush is by sand -blasting. This is usually done to the 
sheets before working them, first sand-blasting and then scratch- 
brushing. The effect remains after the articles have been drawn 
32 



498 TOOL-MAKING AND 

up, as the metal works in much the same manner as lithograph 
sheets would, in the working of which, as is well-known, the 
designs are not marred. 

There is still another method for producing a very pretty 
frosted effect on aluminum. It consists of first sand-blasting 
and then frosting by " dipping." A great many varieties of 
finish on aluminum can be obtained by suitable combinations of 
these treatments. 

To secure a pretty mottled effect on aluminum the article 
should first be polished, then the scratch brush-applied, and then 
the surface burnished with a soft pine wheel which should be 
run at a very high rate of speed. By careful manupulation regu- 
lar or irregular patterns of mottling can be obtained. 

The cheapest and most economical way of producing articles 
with finished surfaces from the sheet is to treat the sheets as 
follows : After removing all grease and dirt from the metal by 
dipping in beuzin, cleanse in water until the benzin has disap- 
peared, after which the plates may be dipped in a strong 
solution of caustic soda, or caustic potash, holding them in the 
solution until they commence to turn black. Then remove the 
sheets, dip again into water, and then into a solution of concen- 
trated nitric and sulphuric acids. After removing from this 
last bath, w r ash the sheets thoroughly in water, and dry in hot 
sawdust. The finish on the plates can be varied by varying the 
strength of the caustic solution, or by adding a small quantity of 
salt to the full-strength solution. 

BUKNISHING. 

For articles which require to be burnished a steel burnisher or 
a bloodstone will give the best results. When burnishing the 
use of a mixture of melted vaseline and crude oil as a lubricant, 
or a solution composed of three tablespoons of borax dissolved 
in a quart of hot water with a few drops of ammonia, will add 
to the finish of the work. 

ENGKAVING AND CHASING ALUMINUM. 

A great deal of engraving is now being done on aluminum, 
such as on finished picture-frames, cups, trays, book-covers, 



INTERCHANGEABLE MANUFACTURING. 499 

match-safes and similar articles, and for this work the best lubri- 
cant to use on the tools is naphtha or crude oil. A mixture of 
crude oil and vaseline also is good. However, the naphtha will 
be found the best, as it will not affect the satiny finish around 
the edges. Besides the use of a proper lubricant when engrav- 
ing aluminum, considerable skill is necessary in the making and 
use of the cutting-tool. A tool made similar to a turning tool 
for aluminum, finished to a sharp, keen point with lots of clear- 
ance, will work excellently. 

A property that makes pure aluminum very valuable for 
many purposes lies in its ability to withstand the action of acids. 
While the metal is easily affected by alkalies, the strongest 
acids do not injure it to any noticeable extent in fact, acid acts 
on it in much the same manner as on platinum. For parts of 
apparatus which have to be immersed in strong acids for consid- 
erable periods, parts of aluminum will prove highly efficient. 
One use to which the metal has been put in this respect is for 
hooks for removing photographic negatives from the acid baths. 
Acid funnels of aluminum also have proved a boon to many. 

SOLDEBING ALUMINUM. 

The last, but not by any means the least valuable, process in 
the working and use of aluminum is soldering. To many the 
difficulties experienced in this line have proven a great detri- 
ment to the successful use of the metal for many purposes. The 
uncertainty as to the best solder to use has been one. There are 
any number of solders which have proved fairly successful when 
skill has been employed in using them. The following has 
proven to be the best in practice for soldering the pure metal or 
any of its alloys: Fuse together one pound of block tin, four 
ounces of spelter, two ounces of pure lead, three pounds of 
phosphor tin. With benzin clean all dirt and grease from the 
surfaces of the parts to be soldered and then apply th'e solder 
with a heated copper " iron." When the melted solder covers 
the surfaces completely, scratch through it with a wire brush, 
which will break the oxide and take it up. Spread the solder 
again with the iron and allow to cool. When it is found neces- 
sary to " sweat " aluminum parts together, first clean the surfaces 



500 TOOL-MAKING. 

as described for soldering, then heat the parts until the solder 
flows freely over them, scratch through with the wire brush, 
wipe with clean waste, and clamp together. A first-class joint 
will result. 

ALUMINUM AS AN ABRASIVE. 

Aluminum, despite its metallic character, can be used as an 
abrasive for sharpening knives. It has the structure of a deli- 
cately grained stone, and under friction gives an extremely fine 
mass which adheres powerfully to steel. Consequently, blades 
sharpened on aluminum rapidly take a thin, sharp edge which 
cannot be produced by the best stones. If knives are passed 
with utmost care over a razor stone, the edge, when magnified 
1,000 times, shows irregularity and toughness, while edges pro- 
duced on aluminum, when submitted to the same examination, 
appear perfectly straight and smooth. 



CHAPTER XXXII. 

Hints, Kinks, Ways, and Methods of Use to Tool- 
makers and Die-makers. 

NOTES ON CIRCULAR FORMING TOOLS. 

WHEN making circular forming tools always keep the fact in 
mind that the diameter has much to do with their wearing quali- 
ties ; and that unless their diameter is proportionate to the diam- 
eter of the work satisfactory results will be hard to obtain. 

In Fig. 572 are shown two circular tools of 1^ and 2 inches 
diameter, respectively, both cut out \ inch below centre, as they 
would be if intended to operate on the front side of the machine 




D 



FIG. 572. 

or at the back side with the work running backward. Although 
shown in this position, the principle involved is of course the 
same as though the tools were placed the other side up, the tool- 
post being bored out above the centre-bore of work spindle, in- 
stead of below, as in the case referred to. 

Referring to Fig. 572 it is easy to see that the cutting-edge of 
the larger tool would have much greater endurance than that of 
the smaller, the rake or clearance of the latter being excessive. 
This difference of rake in circular cutters must of course in- 
crease with the difference in diameter of the cutters, provided 
the cutting-edges are located at the same distance from centre. 
The case is similar to that in Fig. 573, where are shown side by 

501 



502 



TOOL-MAKING AND 



side two straight cutting-off tools, the clearance of one ground 
as at E and the other as at F. The angle of clearance of R is 
practically the same as that of the larger circular tool in Fig. 




FIG. 573. 

574, while that of F coincides with that of the smaller tool and 
shows much less durability than the tool ground as at E. 

It is usually the best practice in making tools for a certain 
size machine to keep them as closely to one diameter as possible. 
In the larger machines cut out the tool y\ inch from centre, 
and of course bore the tool -post a corresponding amount above 
or below the centre, according to which side up the tool is to be 




FIG. 574. 

operated. For the smaller machines make the tools of less diam- 
eter, cutting them out J inch from centre and boring the post to 
correspond. In Fig. 574 line A B represents centre of work, CD 
centre of large cutter, showing the same cut T 3 g inch below cen- 
tre, while C D represents centre of small cutter and shows the 
same cut inch below centre. The clearance of both cutters is 
practically identical. 

A KINK FOE DRAWN WORK. 

A sharp corner under a shoulder or flange is often a very de- 
sirable thing, and one generally considered impossible in drawn 



INTERCHANGEABLE MANUFACTURING. 



503 



work because of the necessity of a round corner on the die to keep 
the metal from tearing while being drawn through the die. There 
is a method, however, of doing this that is quite successful, as 
shown by the accompanying sketch, and it seems to be about the 
only way it can be done. The "kink" consists in making the 
punch a series of steps as per Fig. 575, with round corners instead 
of a parallel one, as in the usual practice ; the steps to be about as 
far apart as the depth to be drawn ; and the difference in diame- 
ter of steps to be determined by thickness of stock. The blank, 
instead of being a round disk, is a washer, the outer edges held 
not too tightly by the usual pressure ring or plate, and the end of 
the punch to be a little larger than the hole in the washer. The 




PRESSURE RINO 




FIG. 575. 

punch will open the hole to the full diameter of the end and turn 
the sharp corner of the disk in the most surprising manner. The 
steps follow each -other rapidly, each one enlarging the hole to 
its own size and carrying the stock down through the die, the 
last step being the finished size of the interior of work, and the 
hole in the dies being the outside diameter of same. A die like 
this needs a press with a good long stroke, depending, of course, 
upon the character of the work. 

BBASS-WOEKING TOOLS AND THEIE USE. 

Figs. 576 to 583 illustrate brass-working tools for hand 
work. No. 576 is a flat planishing tool- which is used for finish- 



504 



TOOL-MAKING AND 



ing and smoothing down flat surfaces, and also convex surfaces. 
No. 577 is a flat plauisher, ground at an angle so as to allow of 
getting into a corner. Nos. 578 and 579 are for finishing in round 
corners or roughing concave surfaces. No. 580 is a small round- 
nose tool which is generally used for roughing out work or get- 



/wv\ s=i 





Flat finishing or planishing tool. 
Flat tool ground at angle. 
Large round-nose tool. 
Medium rouud-nose tool. 
Small round-nose roughing tool. 
Parting or cutting off tool. 
Outside thread chaser. 
Inside thread chaser. 



FIGS. 576 to 583. 




ting under the scale of a casting. No. 581 is the proper form 
of hand cuttlug-off or parting tool. None of these tools should 
have any top rake; on the contrary, they should be ground 




FIGS. 584 to 591. 

slightly the other way and carefully stoned on an oil stone. 
Nos. 582 and 583 are hand thread chasers, which are respectively 
for outside and inside threads. 

The tools shown in Figs. 584 to 591 are for use in the Fox 
lathe. The hook tools which are used in the back head of the 
machine closely resemble the regular inside tools, except that 
the point is turned the other way for outside work. Sometimes 



INTERCHANGEABLE MANUFACTURING. 505 

a tool-holder similar to that shown with set-screw is used with, 
small inserted cutters. Give these tools no top rake and no 
difficulty will be encountered in their use. 

By grinding a twist drill as indicated at B all danger of 
drawing-in will be avoided ; that is, grinding the lips flat for a 
short distance. On a small drill the whole point may be ground 
flat to obtain the best results. 

The flat hand drill illustrated is the best for rough- boring a 
hole in a solid piece. A series of such are used for taper holes, 
the larger being used first and the others following to the proper 
depth to make about the required taper. This is then reamed 
out to the exact taper with various tools. A flat reamer is often 
employed with good results, especially for roughing. For finish- 
ing it is very apt to chatter unless packed on each side with a 
piece of hard wood of about the right shape to conform to the 
hole, Sometimes a reamer with a single large flute, as shown, is 
used with good results. It is relieved nearly all the way around. 
For finishing, it is hard to beat the old reliable square reamer 
as shown at 590. This reams a nice smooth hole as it fills up 
with chips enough to prevent chattering, and it starts well if 
carefully ground and honed on an oil stone. 

GRINDING TWIST DRILLS FOR CUTTING A SECTION 

OF A HOLE. 

In order to drill holes in which part of the drill lias to cut a 
section of a hole as shown in the sketches Figs. 592 and 593 the 
drill should be ground as shown in Fig. 593. It will then be 
found as easy to drill the holes straight as if drilling a full hole. 

To start the drill, use an ordinary drill, drilling just deep 
enough to enter the blades of the drill as ground in Fig. 593 ; or 
a jig may be used to guide the drill in starting. 

TURNING ANB TRUING RUBBER. 

The medium-hard compositions of rubber work very nicely 
with a diamond-point tool, ground a little round on the point 
and given a sharp rake. The tool should be hardened very hard, 
as there is sufficient fine grit in the rubber to wear the edge 



506 



TOOL-MAKING AND 



badly. The speed is governed by the ability of the tool to stand 
up to the work, and is slower in proportion as the rubber is 
harder. 

Soft-rubber articles cannot be cut satisfactorily with any kind 
of a tool ; the best and quickest way is to grind them down. In 
fact, grinding makes the most satisfactory job, whether the rub- 
ber is hard or soft. 

The grinding may be done in a lathe, using an overhead drum 
for driving the wheel and bolting the wheel arbor to the tool- 
post block. 

In plants where electricity can be had a small direct-con- 
nected motor, with flexible cord and plug, makes the most con- 




FlG. 593. 



venient drive, as it is readily detached and put away when not 
in use, leaving plenty of head room over the machine, a quite 
important detail in shops where most of this work is done, and 
where one or two lathes have to do all the work, large and small. 
The best results are obtained by using cast-iron disks for 
wheels, 8 to 10 inches in diameter and 1^ inches thick, with, a 
groove 1 inch wide and inch deep turned in the face. This 
groove is filled with strong twine, laid on tight in hot glue and 
then covered with several coats of glue and No. 40 emery. 
These wheels are to run dry. 



INTERCHANGEABLE MANUFACTURING. 



507 



PATENT TOOL-HOLDERS. 

Figs. 594 to 600 show a complete set of the tools that with a 
straight tool-holder will accomplish all ordinary lathe work. 

In gripding these tools always take them out of the holder, 
otherwise they will be too heavy and liable to heat when placed 
against the emery wheel. If the cutter alone is held in the hand 



/ 

f) 

L_ 




\ 
^ 




= 




^ 




III! 

JIM 


X 


/\ 
^ 


^ 


ffoS^ 




V 




K 



FIGS. 594 to 600. 

it gives timely warning, by becoming too hot to hold comforta- 
bly, and is cooled off before it gets hot enough for the temper to 
be drawn. 

HARD-SOLDERING. 

In the operation of hard-soldering, if the action of heat and 
the nature of the metals in hand are understood, there should be 
no trouble in obtaining a good sound joint, provided the proper 
facilities are available. Jewellers, as a rule, are very painstak- 
ing in their preparatory work, rubbing borax paste upon slate, 
exercising great care to avoid touching the joint with the hands, 
so as to have chemically clean metallic surfaces, etc. This is all 
correct, theoretically, but some machinist workmen also pay all 
attention to these details, and yet lose sight of the more impor- 
tant fundamental principles, especially those pertaining to tem- 
perature. In a large portion of the hard-soldering to be done in 
the average shop, the observance of these minor details first 
referred to would involve considerable trouble. These may be 
safely ignored to a large extent if the applications of flux, solder, 
and temperature are properly made. 

Have the joint as tight as possible, to prevent the solder from 
running through without filling. Apply the flux paste before any 
heating is done, and do not put the solder on until the work is 
about a low red heat, depending on the character of the work, 



508 TOOL-MAKING AND 

metal, shape, etc. Apply the heat to the joint rather tlian to 
the solder, and if the solder runs immediately as it is used, have 
no fears as to the success of the job. In cases where a joint can- 
not be drawn tight, fill up with wire, scrap metal, fillings, etc., 
of the same metal as the work. This may also be applied to the 
outside of the joint if it is desired to retain solder for reinforce- 
ment. 

If these rules are adhered to, it will be unnecessary to mix 
your flux paste on slate, and slight fingering will not prevent 
the making of a good joint. However, cleanliness is a trait to 
be cultivated, and is desirable in all soldering operations. If 
the joint is not reasonably clean, solder will not flow readily, 
more being required to dispel or vaporize the grease or other 
foreign matter. 

SPEED OF PULLEYS AND GEARS. 

In any system of pulleys or gears the general rule holds that 
the product of the diameters or number of teeth of the driving 
wheels and the number of revolutions per minute of the first 
driver must equal the product of the diameters or number of 
teeth of the driven and the number of revolutions per minute of 
the last driven wheel. 

The most frequent pulley calculations in the machine-shop re- 
late to the speeds of machines and countershafts, for which we 
have the four following rules, based upon the above principle. 

First, speed of pulley on machine given, to find speed for 
countershaft. Multiply the number of revolutions per minute 
of the machine pulley by its diameter and divide this product by 
the diameter of the driving pulley on the countershaft. 

Second, speed of countershaft given, to find the diameter of 
pulley to drive machine. Multiply the number of revolutions 
per minute of the machine pulley by its diameter, and divide 
the product by. the number of revolutions per minute of the 
countershaft. 

Third, speeds of main shaft and of countershaft given, to find 
diameter of pulley on. countershaft. Multiply diameter of main 
pulley and divide by number of revolutions per minute of coun- 
tershaft. 



INTERCHANGEABLE MANUFACTURING. 509 

Fourth, speed of countershaft given, to find diameter of 
pulley for line shaft. Multiply number of revolutions per min- 
ute of the countershaft by the diameter of the pulley belting 
with the main line, and divide the product by the number of 
revolutions per minute of the line shaft. 

ETCHING STEEL. 

For etching names, dates, designs, etc., in steel, use any of 
the following recipes: 

No. 1. Iodine, 2 parts; potassium iodide, 5 parts; water, 40 
parts. 

No. 2. Nitric acid, 60 parts; water, 120 parts; alcohol, 200 
parts ; copper nitrate, 8 parts. 

No. 3. Glacial acetic acid, 4 parts; nitric acid, 1 part; al- 
cohol, 1 part. 

BOEING LONG CAST-IRON TUBES. 

When boring long cast-iron tubes of large diameter say 15 
inches excellent results may be attained by using kerosene as a 
lubricant, and a "packed, bit" of the type used for gun-boring. 
Holes of the smoothness of glass will be the result. 

TINNING CAST IRON. 

The following tinning for cast iron will turn out whiter and 
harder than that with tin alone : Iron, 6 parts ; tin, 85 grammes ; 
nickel, 9 grammes. Dissolve the three metals in hydrochloric 
acid. This alloy will adhere well to the cast iron and present a 
very brilliant surface. 

All tanks used for pickling cast iron in vitriol should be lined 
with lead and the seams burned together, not soldered. When a 
pickling tank is lined with zinc it will last but a short time 
under the action of the acid. Solder is also acted upon. 

A HANDY DIE AND TOOL-MAKER'S CLAMP. 

In Fig. 601 are shown sketches of a very handy clamp. It 
may be used for many purposes other than the one indicated. 
In this case it does away with the making of templets in die- 



510 TOOL-MAKING AND 

making after the master blank has been made. First, the exact 
centre of the die blank is found ; then the blank is placed in its 
proper position on the face and clamped there as shown in the 
sketch. Then the outline of the blank is scribed. 

The clamp may also be used to hold the steel block for the 




F4G. 601. 

punch securely against the die face ; thus facilitating the turning 
of the work to the light and examining the inside. 

LUBRICANT FOR DRAWING SHELLS. 

Take one pint of common lard oil, two pounds of opodeldoc 
soap, eight gallons of water ; steam or heat until warm. Attach 
a square pan to the front of the press and keep the shells well 
covered. With very small shells, such as primers or pencil tips, 
it will be necessary to keep the solution warm ; but with large 
shells this will not be necessary. This is the best lubricant for 
drawing shells from thin metal that I have ever come across. 

TO GLUE LEATHER TO IRON. 

To glue leather to iron, paint the iron with some kind of lead 
color, say white lead and lamp-black. When dry, cover with a 
cement made as follows : Take the best glue procurable, soak it 
in cold water till soft, then dissolve in vinegar with a moderate 
heat, then add one-third of its bulk of white pine turpentine, 
thoroughly mix, and by means of vinegar make it the proper 
consistency to be spread with a brush. Apply the cement while 



INTERCHANGEABLE MANUFACTURING. 511 

hot ; draw the leather on or around quickly, and 'press tightly in 
place. In case of a pulley, draw the leather around tightly as 
possible, lay and clamp. 

KEEPING NOTE-BOOKS. 

Before concluding this chapter I feel that it will be well to 
present a few remarks on the advantage of keeping note-books 
in which to note and preserve the valuable and useful informa- 
tion which abounds in the mechanical press and which one be- 
comes informed of through association with brother mechanics, 
or through experience and practical observation. It is a fact 
that the diffusion of knowledge is retarded greatly by mechanics 
in general trusting to their memory for the preservation of valu- 
able information, instead of to more reliable means. 

The most simple way to gain by one's reading and observa- 
tion is to determine to fix upon some plan within one's capacity, 
means, and opportunity those which come in one's daily routine 
and to follow it preseveringly, regularly, and punctually, as an 
important factor in one's daily duties. Many men owe their suc- 
cess in life to the keeping of note-books in which they had noted 
information which, while of little moment at the time when writ- 
ten, proved of inestimable value at a later date. 

A good way is to keep three note- books : one for jotting down 
items and notes and sketches which come to one in the shop 
through observation, hearsay, and experience. This book should 
be of pocket size. The second book should be a large, strongly 
bourd manuscript book haA r ing horizontal ruled lines. In this 
one can write something every evening something one has read 
in a mechanical paper. The third book may be a scrap -book of 
the usual kind, in which sketches, small drawings, diagrams, and 
illustrations of new machines and appliances may be pasted. By 
following this suggested plan one will become a close and accu- 
rate observer, an enlightened and well-informed man, and a bet- 
ter mechanic; no matter what line he is engaged in, he will not 
only gain in knowledge, but may gain financially by publishing 
in the mechanical press any information which has come to him 
through experience and observation and which appears to be 
new or novel. 



CHAPTER XXXIII. 

The Value of Up-to-date Fixtures and Machine 
Tools. Conclusion. 

IN the preceding chapters I have endeavored to illustrate and 
describe the most approved construction and methods for accom- 
plishing the best results in modern tool-making and interchange- 
able manufacturing ; and before drawing this work to a close I 
have thought it fitting to conclude by discussing the value of im- 
proved and labor-saving fixtures and machines, and to present 
what to me appears to be the only system by which the Ameri- 
can machine-shop or manufacturing plant can retain its place at 
the head of the world's list of industrial supremes. 

LACK OF KNOWLEDGE OF MACHINE TOOLS. 

Notwithstanding the vast amount of literature that is being 
circulated to-day describing and illustrating the uses of new 
machines, appliances, etc., for economic manufacturing, there is 
a woful lack of knowledge among shop managers, superintend- 
ents, and proprietors as to their possibilities, and among me- 
chanics of how to operate them properly. If any one has an ex- 
cuse for this lack of knowledge it is the mechanic ; for while the 
heads of establishments are constantly receiving printed matter 
describing what the machine can do, and have representatives 
calling on them to discuss the labor-saving features of the ma- 
chines they are selling, the mechanic has to rely solely upon the 
knowledge gained previously in the running of other similar 
machines to assist him in mastering the details in the operation 
of the new one. 

"UP-TO-THE-MINUTE" MACHINE TOOLS 

To-day the amount of money and time that is wasted every 
day in shops is apparent to very few. Even superintendents, 
shop managers, and master mechanics fail to realize the economy 

512 



INTERCHANGEABLE MANUFACTURING. 513 

that can be effected in the production of duplicate metal articles 
and interchangeable machine parts and the increasing of the effi- 
ciency of the output, by replacing worn-out and obsolete ma- 
chines with others that are "up-to-the-minute," equipping them 
with suitable fixtures and tools, and operating them as they were 
designed and built tf> be operated. 

ADVANTAGES GAINED THROUGH THE USE OF 
IMPROVED TOOLS. 

It goes without saying that the most important item in the 
cost of running a modern machine shop or a manufacturing plant 
is the labor bill. The tools and machines in the hands of and 
operated by the workman determine the size of the output to a 
given size of labor account. Thus the advantages to be gained 
in manufacturing by the use of up-to-date machines and special 
tools and fixtures are obvious ; as the cost of the machines and 
the amount expended in the designing and constructing of special 
tools will be quickly balanced on the profit side when the in- 
creased output and the efficiency of the parts produced through 
their use are compared with the results under the old methods. 
Another advantage to be gained through the use of improved 
tools is the almost total elimination of the obtainable results de- 
pending upon the degree of skill and intelligence possessed by 
the workman ; thus allowing of employing less expensive help 
in the manufacture of the required parts. 

The above enumerated advantages gained through the use of 
modern machines and tools should be so thoroughly recognized 
by the executive heads of manufacturing plants that the aim 
should be universal to weed out all inferior tools, and allow to 
remain nothing but the most efficient machines, tools, and fixtures 
in the hands of the workman ; so that the mechanic may produce 
a greater quantity, or a better quality of work, irrespective of 
his degree of skill, and without increased exertion mentally or 
physically. 

IDEAL TWENTIETH-CENT UEY MANUFACTUEING. 

Ideal twentieth- century manufacturing is attained through 

the constant endeavor of shop officials to increase the dividend 
33 



514 TOOL-MAKING AND 

on each dollar of investment. If an old machine can be replaced 
with an improved one which will be capable of producing more 
work, or the same quantity of work with less labor, it should be 
installed. Often the installation of a new machine in place of 
an obsolete one has saved from fifteen to one hundred per cent, 
and over per annum on the investment. Those who doubt this 
assertion have only to inquire of the manufacturers of new ma- 
chines in order to substantiate my claim. 

DEPRECIATION IK MACHINE-SHOP. 

The depreciation of a machine-shop that is merely kept in 
repair will pile up just as fast as better and improved machines 
and tools are installed and used in competing shops. The 
amount of depreciation will not be evidenced by the books; but 
it will go on just the same and dividends will be declared out of 
the inventory not out of the earnings. Of course this depre- 
ciation can in some cases be continued for some years without 
the ultimate end coming in vieAV. But at the best the smash will 
only be postponed and the result will be worse. Though this 
simple decline in the plant's value may not be considered of 
much moment, the increased cost of its product and the inferior 
efficiency of the same as compared with that of competing com- 
panies will eventually ruin it. While it is not always possible 
to replace all or even the greater part of an obsolete equipment 
with new machines, it can be done gradually. Keep putting in 
better and more efficient tools and machines every year and the 
plant will keep its place in the front ranks of prosperous establish- 
ments. 

CAUSES OF DEPRECIATION IN SHOPS. 

Lack of concentration, of specialization, of information, and 
too much attention to other duties in the general run of business 
usually account for the depreciation of a plant ; as the cost of 
installing up-to-date fixtures for the duplicate production of 
small repetition parts and the replacing of old machines with im- 
proved ones will not ordinarily exceed the extra cost per year of 
production by old methods and of running and keeping in repair 
the old machines. In fact, there is no excuse for the non-installa- 
tion in any shop of a machine which will turn out more and bet- 



INTERCHANGEABLE MANUFACTURING. 515 

ter work than an old oue, as the manufacturers of such machines 
are always willing to assume nil cost of demonstrating their effi- 
ciency and labor-saving qualities. 

THE SELECTION OF MACHINES FOE MANUFAC- 
TURING PURPOSES. 

Again, in the selection of machines for manufacturing pur- 
poses, extremes should be avoided. We have to select from the 
" universal type, " the " special, " and the " happy medium. " The 
"universal " machine unsually lacks efficiency ; and it is difficult 
to produce interchangeable machine parts of a high grade in it. 
The " special " machine lacks working range; and unless large 
quantities of work of the same kind are constantly required the 
machine is frequently idle. The "happy medium," then, is the 
one for most shops. 

UNIVERSAL EQUIPMENT VS. WORKING-RANGE 
EQUIPMENT. 

In the average machine-shop or manufacturing plant of to- 
day important changes frequently occur. In such establishments 
the efficiency of the manager lies in his ability to have the shop 
ready for such changes changes which frequently entail the 
entire product of the works. Thus a well-informed and prac- 
tical manager is able to make changes in the product and at the 
same time avoid an excessive depreciation of the shop's value. 

The properly equipped machine-shop of to-day has an equip- 
ment which is either universal or at least within its working 
range and which will at the same time possess the greatest effi- 
ciency. Thus the jobbing shop will have a universal equipment ; 
while the machine-tool shop will have a working-range equip- 
ment. It is to such plants that we owe our manufacturing 
supremacy, as they are the ones who compete with and under- 
sell foreign manufacturers on their own ground. 

CAUSE OF THE GREAT DEVELOPMENT IN MACHINE 

TOOLS. 

The introducing of innovations and the adaptation of radical 
ideas are constantly occurring all along the lines of machine-tool 
manufacturing and the production of mechanical apparatus. 



516 TOOL-MAKING. 

The cause of this wonderful growth in the "number of types of 
machine tools, and their great capacity for fine work, may be 
directly traced to the great improvements in electrical devices, 
necessitating numbers of machine tools of improved construction 
to produce their complicated parts. This has been the cause of 
the great activity in machine-tool improvement and building be- 
cause, first, it called for new methods and facilities for manu- 
facture. 

Another event having an effect on the designing and manu- 
facturing of machinery entirely unlocked for at the time of its 
inception was the manufacture of the bicycle. This event 
brought out the capabilities of the American mechanic as noth- 
ing else had ever done. It demonstrated to the world at large 
that he and his kind were capable of designing and making 
special machinery, tools, fixtures, and devices for economic man- 
ufacturing in a manner truly marvellous ; and has led to the in- 
stallation of the interchangeable system of manufacture in a 
thousand and one shops where it was formerly thought to be 
impracticable. 

The autocar, automobile, and autocycle are the latest creations 
to demand the attention of the designer, tool-maker, and the ma- 
chinist. It is in the perfecting and manufacturing of these 
twentieth -century marvels of mechanism that they are showing 
the world that to them nothing is impossible, and that the in- 
genuity and skill which perfected the "dollar watch" will also 
prove adequate to produce an " automobile for the million." 
Forward ! 



INDEX. 



ABRASIVE, aluminum as an, 500 
Accurate jig-making, processes of, 43 

jigs, 36 

work, milling fixtures for, 141 

work on dies, special machines for, 355 
Acetylene gas burners, drill jig for, 68 
Action of sub-press dies, 466 
Advantage gained through the use of improved tools, 513 

in the use of special tools, 223 

of the end cut in boring tools, 248 
Aligning cutter-grinder centres with micrometer, 272 

lathe centres with micrometer, 271 

Allis-Chalmers Company, production of perforated metal by, 439 
Aluminum, annealing, 497 

as an abrasive, 500 

base casting, drill jig for, 92 

bending and forming dies for, 496 

burnishing, 498 

cutting dies for, 495 

difficulties encountered when working, 492 

drawing dies for, 495 

engraving and chasing, 498 

grades and alloys of, 493 

lubricating when working, 494 

polishing and finishing, 497 

processes and methods for working, 492 

pure metal vs. alloys of, 492 

secrets in working, 493 

sheets, necessary to lubricate before working, 413 

shell, die for blanking and drawing, embossing, 410 

shells, blanking and drawing, 413 
drawing, 496 

soldering, 499 

spinning, 496 

working the metal, 493 

American Machinist, extracts from articles in, 121-251 
American mechanic, capabilities of, 516 

tool-maker, 26 

517 



518 INDEX. 

Angle plate, milling one, 125 
Annealing aluminum, 497 

and lubricating shells in drawing, 368 
Armature disks, 453 

machines and dies for, 454 
of large diameters, 454 
piercing and perforating, 437 
segment blanks, 460 

notching press, 460 
segments, 459 
what constitutes, 454 

Art goods, dies for stamping and embossing, 468-478 
of sheet-metal working in dies, 365 
of swaging, 477 

Assortment of milling cutters, picking, 232 
Attachment for cylindrical perforating, 433 

for drilling and tapping in the turret-lathe, 183 
for forming pieces from bar in turret-lathe, 163 
Automobiles for the million, 516 

B 

BAG clasps, dies for sheet-metal, 403 
Bath for cutters, hot lead, 241 
Bearing bracket, drill jig for, 62 

milling fixture for, 131 
Bending and forming dies for aluminum, 496 

nice job in, 416 

Bicycle handle-tips, moulds for making, 293 
Blades, holding milling-cutter, 229 
Blanking dies, cheap, 372 
Blanks, fining for drawn shells and cups, 369 
Boring bars and reamers, 224 

brackets and spindle heads, special machines for, 214 

drill jig fqr power-press bolster, 102 

drill-press tables, 220 

fixtures, drill-press and, 208 

long cast-iron cylinders, 509 

rig for drill-press, 212 

Bottomless shells, perforating small close patterns in, 435 
Bottoms, double seaming of round, 441 

seaming burred-edged, 441 
Box lid fastening plates, dies for, 389 

straps, piercing and spreading dies for, 385 

tool for turret-lathe, 169 

tools for screw machine, four special, 190 
Bracket, bearing, drill jig for, 62 

milling fixture for, 131 
Brass, bronze, and copper dies, 477 

clock wheels, punching, 376 



INDEX. 519 



Brass parts, reaming holes in, 258 

rings, making thin, 305 

working tools, and how to use them, 503 
Broaches and broaching, 260 

some points about, 265 
Broaching, interesting job of, 262 

its relation to sheet-metal work, 267 

operation of, 261 

Bronze, brass, and copper dies, 477 
Brown and Sharpe tool-rooms, 39 
Burner shells, perforating, 434 
Burning cutters, 237 
Burnishing aluminum, 498 
Burred -edged bottoms, seaming them, 441 
Bushing holes, button method for locating, 43 
locating and finishing in large jigs, 48 
Button method for locating drill bushing holes, 43 

C 
"CAM body, drill jig for multiple, 81 

milling machine, special, 337 

set of tools for machining, 300 
Cams, drill jig for, 78 

indexing dial jig for, 109 
Casting to be jigged, patterns for. 47 
Cast iron impression cylinder, drill jig for, 98 
tank for pickling, 509 
tinning, 509 

Cause of great development in machine tools, 515 
Causes of depreciation in machine shops, 514 
Centre reamers, 257 

Chasing designs in mountings of metal, 472 
Cheap blanking dies, 372 - 

jigs, 35 

Chief factors in machine manufacturing, 160 
Chucks for eccentric straps, 340 

for gasoline engine cylinders, 342 

for holding pulleys in the turret lathe, 170-172 

for turning eccentric rings, 338 

two eccentric cams, two-nose, 341 
Circular forming tools, 253 
notes on, 501 

shearing machines, 456 

shells, large drawing dies for, 391 
Clamp for die and tool-makers' use, 509 
Cloth, hollow cutters for punching, 297 
Coins, dies for, 468-469 
Cold swaging process, 479-482 
Collet spring chucks, 310 



520 INDEX. 

Combination dies for embossed work, 475 

Compound dies for parts of telephone transmitter cases, 423 

Constructing simple drill jigs, 43 

special, devising and, 300 

Construction and design of novel drill jigs, 106 
of milling machines, improvements in, 122 
Copper, bronze, and brass dies, 477 
Corkscrews, machine for twisting, 327 
Cost vs. longevity of the sub-press, 463 
Counterbores, 254 
Counterboring, 254 

large casting in drill-press, facing and, 352 
Cup centres, finishing, 222 
Curling and wiring processes, 447 

deep shells, 452 

punch and die, 452 

the edges of circular shells, 447 

of drawn shells, 450 

Cut-off and forming tool, hand for the speed-lathe, 315 
Cutters, assortment of milling, 232 

burning, 237 

classified, milling, 224 

degree of hardness in, 241 

end mill, 227 

gang milling, 235 

hardening, 239 

and tempering, 239 

heating, 240 

and hardening large, 243 

holding inserted blades of milling, 229 

injury in hardening, 241 

inserted teeth, 228 

interlocking, 235 

lead bath for, 241 

limits of inaccuracy in, 229 

making milling, 235 

plunging, 241 

regrinding of, 231 

sand-blasting, 242 

selecting a set of, 232 

shell and end milling, 234 

side clearance in, 228 

speeds and feeds of, 236 

spindle surface, milling, 234 

standard styles and sizes of, 226 

steel for, quality of, 231 

suggestions for milling with, 238 

test for hardness in, 242 % 

undercut teeth, 226 



INDEX. 521 



Cutters, use and abuse of milling, 230 

warping, 241 
Cutting dies for aluminum, 495 

edges desirable for boring tools, number of, 246 

leather, cloth, and paper with dinking cutters, 397 

soft-rubber articles, 506 
Cylinders, boring cast-iron, 509 
Cylindrical perforating, attachment for, 433 

D 

DAYTON swaging machine, 485 
Decorated-sheet metal articles, drawing, 369 
Deep hole drilling, 244 

shells from sheet metal, drawing, 393 
Deflecting device for seaming machines, 443 
Degree of hardness in cutters, 241 
Depreciation in machine-shops, 514 

in shops, causes of, 514 
Depth to which shells may be drawn, 368 
Design and manufacture of milling cutters, 226 
Designer, the, 29 
Device for turret-lathe, 190 

Devising and constructing special tools, ability to, 300 
Dies, and tool-makers' clamp, 509 
art goods, 468-478 
bending and drawing, 496 
brass, 477 

clock gears, 376 
bronze, 477 
cheap blanking, 372 
coining, 468-470 

compound, for telephone transmitter cases, 423 
copper, 477 
curling, 452 

cutting, for aluminum, 495 
drawing for aluminum, 495 

for large shells, 391 
engraving, 468-478 
filing machine for, 361 
for box -corner fasteners, 383 
bending and forming, 416 
blanking and drawing aluminum shells, 413 
embossing jewelry, making, 469 
forming large sheet-metal articles, 474 
jewelry, 468-478 
sheet-metal bag clasps, 403 
gang sets for eyelets in one operation, 420 
hand-finishing vs. machine-finishing of, 356 
bobbin g, 468-478 



522 IHDEX. 

Dies, improved piercing, 388 
machine for filing, 358 
making hobs and sinking embossing, 476 
making kink for, 314 
milling machines, use of, 357 
patterns, modelling intricate, 472 
piercing and spreading, 385 
punching and curling, 399 
without waste in, 380 
shaper for, 358 
shearing, 373 
sinking attachment for, 358 

with hobs, 468-478 
slotter, small, 360 
small hole finishing, 374 
special machines for accurate work on, 355 
sub-press, action of, 466 
triple-acting, 410 
water or fluid, 474 

Difficulties encountered in working aluminum, 492 
Disks, armature, piercing and perforating, 437 
cutting armature, 453 
of large diameters, 454 
Double horning and seaming, 443 

seaming bottoms on heavy work, 447 
machine for irregular articles, 445 
of bottoms on special work, 447 
irregular can bottoms, 443 
round can bottoms, 441 

Doubt as to the utility of milling machines, 128 
Drawing aluminum shells, 496 

and forming decorated sheet-metal articles, 369 
annealing and lubricating shells in, 368 
a sharp corner under a shoulder, 502 
deep shells from sheet metal, 393 
dies, for aluminum, 495 

way to construct, 370 
shell from thin metal, lubricant for, 510 
Drawn shells, finding the blanks for, 369 

work processes for, 367 
Drill bushing holes in large jigs, locating, 48 

button method for locating, 43 
notes, 252 

press and boring fixtures, 208 
boring rig, 212 
cup centres, finishing, 222 

facing and counterboring large castings in, 352 
flat tables, boring, 220 
job, a, 306 



INDEX. 523 



Drill-press, milling in the, 311 

round tables, machining, 222 

Drilling and tapping attachment for turret lathe, 183 
deep holes by Pratt and Whitney method, 249 
holes in helical surface, 313 
jigs, constructing large, 96 

simple, 43 
for acetylene gas-burners, 68 

an aluminum base casting, 92 
a spiral line of holes around a cylinder, 106 
bearing bracket, 62 
cams, 78 

cast-iron impression rollers, 98 
dovetailed slide bracket, 101 
drilling and countersinking, 76 
drilling and hobfacing, 83 
drilling and tapping, 115 
multiple cam body, 81 
nailing-machine cross-head, 96 
odd-shaped casings, 70 
power-press bolster, 102 
round castings in pairs, 74 
small accurate work, 89 
spider castings, 115 
the speed lathe, 66 
typewriter bases, 85 
indexing dial for small cams, 109 
intricate and positive, 81 
novel, 118 

design and construction, 106 
points to remember when making, 104 
simple, 42 

fourteen-hole, 59 
special milling and, 354 
their use, simple, 64 
with indexing fixtures, 109, 111, 114 
job on the planer, 308 
set of milling and, 348 
small thread dies, jig for, 325 
types of simple jigs, 55 
Duplicate work in screw machine, method for finishing, 195 

E 

ECCENTRIC cams, two-nose chucks for machining, 341 

rings, chucks for turning, 338 

straps, chuck for machining, 340 
Effects of work accomplished by swaging, 491 
Eli Whitney, 19 



524 INDEX. 

Embossed work, combination dies for, 474 
Embossing, blanking, and drawing, 410 

jewelry, making dies for, 469 
End cut in boring tools, advantage of, 248 
Engraving a hob for sinking medal dies, 468 

and chasing aluminum, 498 

dies for embossing jewelry, 468-470 

machine, special, 334 
Etching steel, how to do it, 509 
Examples of special uses of height-gauge, 274-278 

of micrometer, 271 
Expansion reamers, 258 
Eyelets, gang punch and die for, 420 



FACE milling, fixtures for, 139 

Facing and counterboring large castings in drill-press, 352 

tools, 254 
Factors in machine manufacturing, 160 

in the successful use of milling fixtures, 141 

involved in designing of drill jigs, 40 
Feeding sheet metal to the sub-press, 466 
Feeds and speeds for milling cutters, 236 
Fibre washers, special tool for cutting out, 329 
Filing dies, machines for, 358 

machine, 361 

Finding the blanks for drawn shells, 369 
Finishing cup centres of drill-presses, 222 

of dies, hand vs. machine, 356 
Fixtures for adjustable stops and spindle racks, jigs and, 320 

for milling drill-press tables, 152 
Flaking stick, its use, 311 
Flat jigs, their use, 32 
Follow dies, gang and, 366 
Forming irregular pieces from the bar, fixture for, 163 

pieces of irregular outline, fixture for, 200 

tools, notes on circular, 501 

Four special box tools for the screw machine, 190 
Fourteen-hole drill jig, 59 

G 
GANG and follow dies, 366 

die for metal box -lid fastening plates, 389 
milling cutters, 235 
fixtures for, 138 

punch and die for producing eyelets in one operation, 420 
Gasoline engine cylinders, chuck for machining, 342 
Gauges, 32 
Gears, speeds of pulleys and, 508 



INDEX. 525 



Gelatin moulds, making, 472 

Glue for leather and iron, 510 

Grades and alloys of aluminum, 493 

Great development in machine tools, causes of, 515 

Grinder, aligning cutter, centres, 272 

Grinding of cutters, 239 

rubber, 506 

twist drill for cutting section of hole, 505 
Grit in rubber, 505 

H 

HAMMERING and swaging, 479 
Hand cut-off and forming tool for speed lathe, 315 
finishing vs. machine 'finishing of dies, 356 
reaming, 259 

Hardening and tempering of milling cutters, 239 
injury in cutters, 241 
test for, 242 

Hardness, degree of, in cutters, 241 
Hard -soldering, 507 
Heating and hardening large cutters, 243 

the steel, 240 
Heavy work, jigs for, 34 
Height-gauge and its use, 274 

examples of use of, 274-278 
locating holes with, 275 
shop use of, 268 
Holding cutter blades, 229 

devices for jigs, locating and, 41 
Hollow cutters for punching leather, cloth, and paper, 397 

drill, boring spindles with, 251 
Home-made reamers, 259 
Horizontal swaging machines, 489 
Horning and seaming processes, 440 

double seaming and, 443 

How to construct a sub-press, 463 

drawing dies, 370 

I 

IDEAL twentieth-century manufacturing, 513 
Improved piercing die, 388 

tools, advantages gained through the use of, 513 
Improvement in construction of milling machine, 122 
Increasing the size of worn reamers, 260 
Indexing dial jig for small cams, 109 

milling fixtures, 147 

plates, jigs with, 109, 111, 114 
Injury in hardening cutters, 241 
Inserted teeth, holding, 229 
cutters, 228 



526 INDEX. 

Inside blank-holders, 392 

Installation of armature disk punching machinery, 458 

of the interchangeable system, 23 
Intel-changeability, 20 

Interchangeable manufacturing, milling machines and, 120 
origin of, 19 
to-day, 22 

Interesting job of broaching, 262 
Interlocking cutters, 285 
Intricate and positive drill jigs, 81 

machinery, modern manufacturing of, 23 
Irregular articles, double seaming machine for, 445 
Iron and leather, glue for, 510 

J 

JEWELIIY, dies for making, 468-478 

making dies for embossing, 469 
Jigs and fixtures, functions of, 30 

bodies, handling large, 52 

box, 33 

cheap, 35 

design, factors involved in, 40 

feet, 53 

flat, 32 

large, 48 

making, processes for accurate, 43 

work on the plain miller, 50 
Jobbing shop work, milling machines and, 120 

K 
KEEPING note-books, 511 

sheets straight while perforating, 438 
Keyseating in the power-press, 315 
Kink, die-making, 314 
Knee type of universal milling machines, 123 



LACK of knowledge of machine tools, 512 
Large drawing dies for circular shells, 391 

drilling jigs, 48 
Lathe chuck, simple, 312 

tool-maker's, 36 
Leather and iron, glue for, 510 

hollow cutters for punching, 397 
Limits of inaccuracy in milling cutters, 229 
Locating and finishing drill bushing holes in large jigs, 48 

and holding devices for drill jigs, 41 

drill bushing holes, button method for, 43 
Lock seam, successive stages of, 441 



INDEX. 527 

Lubricants to use for drawing shells from thin metal, 510 

for working aluminum, 494 
Lubricating and annealing shells for drawing, 368 

M 
MACHINE, Dayton swaging, 487 

die filing, 361 

finishing vs. hand finishing of dies, 356 

for double-seaming irregular bottoms, 445 

for engraving poker chips, 334 

for filing dies, 358 

for twisting corkscrews, 327 

manufacturing, chief factor in, 160 

reaming of brass parts, 258 
with floating reamer, 255 

shops, cause of great depreciation in, 514 

special cam milling, 337 
engraving, 334 

tools, 28 

cause of the great development in, 515 
lack of knowledge of, 512 
up-to-the-minute, 512 

Machinery, extracts from articles in, 244-481 
Machinery for double-seaming round bottoms on cans, 442 
Machines and dies used for perforating armature disks, 454 

horizontal swaging, 489 

rotary swaging, 485 

special, for accurate work on dies, 355 
Machining a cam, special tools for, 300 

a special casting, tools for, 180 

drill columns, 156 

pulleys, detail drawings of special tools for, 172 

round tables, 220 
Making and use of simple dies, 371 

dies for embossing jewelry, 469 

hobs and sinking embossing dies, 476 

impressions of elaborate dies, 473 

thin threaded brass rings, 305 

drill press cup centres, 222 

collet spring chucks, 310 
Manufacture of accurate sheet-metal parts in the sub-press, 461 

of armature disks and segments, 453 
segments, large, 459 

of milling cutters, design and, 224 
Manufacturing, chief factor in machine, 160 

ideal twentieth-century, 513 

of intricate machinery, 23 

origin of interchangeable, 19 

purposes, selection of machines for, 515 



528 INDEX. 

Manufacturing, to-day, ideal interchangeable, 22 
Medal dies, engraving a steel bob for sinking, 468 
Metal box -corner fasteners, "dies for, 383 

patterns, 23 
Method for finishing duplicate work in the screw machine, 195 

for locating drill jib bushings, button, 43 
Micrometer calipers, 268 

reading them, 270 
special uses for, 271 

aligning cutter grinder centres with, 272 

lathe centres, testing for height of, with, 272 

testing lathe centres for alignment, 271 

universal use of, 274 

used as inside calipers, 273 
Milling and drilling jigs, set of special, 348 
Milling-cutters, assortment of, 232 

burning, 237 

classified, 224 

degree of hardness in, 241 

end, 227 

face, 139 

gang, 138-235 

hardening and tempering, 239 

heating, 240 

heating and hardening large, 243 

holding blades in, 229 

injury in hardening, 241 

inserted teeth, 228 

interlocking, 235 

lead bath for heating, 241 

limits of inaccuracy in, 229 

making, 235 

miscellaneous, 152 

plunging when hardening, 241 

quality of steel to use for, 231 

regrinding of, 231 

sand-blasting of, 242 

selecting a set of, 232 

shell and end, 234 

side clearance on, 228 

speeds and feeds for, 236 

spindle surface, 235 

standard types and sizes of, 226 

test of hardness of, 242 

undercut teeth, 226 

use and abuse of, 230 

warping in hardening, 241 
Milling-fixtures, factors in the successful use of, 141 

for accurate work, 141 



INDEX. 

Milling-fixtures for bearing bracket, 181 

for drill-press tables, 152 

for slotting and dovetailing small pieces, 134 

for squaring ends of duplicate pieces, 132 

indexing, 147 

simple, 129 

six simple and distinct types of, 129 
.Milling-machines, compared with other machine tools, 124 

doubt as to the utility of, 128 

improvements in construction of, 122 

in the drill press, 311 

in the tool-room, 125 

knee type of universal, 133 

modern tool-making and, 120 

practice, most vital point in, 236 

spindle racks, milling in, 323 

universal types of, 122 

use of die, 357 

of universal and plain, 120 

utility of, 120 

vertical spindle, 127 
Modeller's wax, making and using, 473 
Modelling intricate die patterns, 472 
Most skilled mechanic in the world, 26 
Moulds, 279 

construction of, 279-299 

for bicycle handle-tips, 293 

for lead balls, 282 

for pencil crayons, 279 

for poker-chips, 296 

for spherical articles, 298 

for telephone receiver pieces, 285 

gelatin, for fancy die work, 472 

how an accurate set of, was machined in the planer, 288 
Movable strippers, 379 
Multiple cam body, drill jig for, 81 
Multi -spindle drilling and tapping attachment for turret-lathe, 183 

N 

NECESSITY to lubricate aluminum before working, 413 
Nice job of bending and forming, 416 
Note-books, how to keep them, 511 
Notes on circular forming tools, 501 

on drills, 252 
Novel drill jigs, 106-118 

O 

OBKHLIN SMITH'S "Press Working of Metals," 267 
Operation of broaching. 261 
34 



530 INDEX. 

Origin of interchangeable system, 19 
Ornamental articles, dies for forming, 472 



PAPER, hollow cutters for punching, 397 

Patent tool-holders, 507 

Patterns for castings to be jigged, 47 

Pencil crayons, set of moulds for, 279 

Perforated metal, production of, by Allis-Chalmers Company, 439 

Perforating and blanking small armature disks, 437 

and piercing, 367 

attachments for cylindrical, 433 

burner shells, 434 

flat and cylindrical sheet-metal articles, 433 

keeping sheets straight while, 438 

large sheets of metal in special designs, 438 

small close patterns, 435 

taper and crowning shells, 434 
Petroleum cans, seaming them, 445 
Pickling cast iron, tanks for, 500 
Piercing and perforating, 367 

and spreading die for box straps, 385 

die, improved, 388 
Plain forming tools, 253 

miller, jig work in, 50 

Planer, accurate set of moulds machined in, 288 
Plunging heated cutters, 241 
Points about broaches and broaching, 265 
Poker-chips, set of moulds for, 296 
Polishing and finishing aluminum, 497 
Polyphase motor, 456 
Positive drill jigs, intricate and, 81 
Power-press, key-seating in, 315 

bolster, drill jig for, 102 
Power-presses used for disk punching, 457 
Pratt and Whitney method of deep hole drilling, 249 
Press, armature disk notching, 460 

tools, simplest clasr: of, 366 

work, 432 

"Press Working of Metals," Oberlin Smith's, 2<i7 
Principal use of sub-press, 462 
Principle of reproduction, great, 29 
Process, cold swaging, 482 
Processes and methods for working aluminum, 492 

for curling and wiring, 447 

for drawn work, 367 

horning and seaming, 440 

of accurate jig making, 43 



INDEX. 531 



Producing parts without waste, die for, 380 
Progress made in the use of power-presses, 355 
Projectiles, reamers for, 257 
Pulleys and gears, speeds of, 508 

set of tools for machining in one operation, 172 
Punching and curling job, 399 

brass clock gears, 376 
Pure metal vs. alloys of aluminum, 492 

Q 

QUALITY of steel to use for cutters, 231 



R 

RAZORS, aluminum for sharpening or honing, 500 
Reading micrometers, 270 
Reamers and reaming, 255 

centre, 257 

expansion, 258 

for babbit metal, 257 

for projectiles, 257 

hand, 259 

home made, 259 

increasing the size of, when worn, 260 

small parts, machine, 258 
holes, 259 

square, 258 

taper of rose, 257 

Reaming holes in the screw machine, taper, 256 
in the turret-lathe, 255 
in thin disks, 255 
in two kinds of metals, 257 
taper holes in cast iron, 256 
with the floating reamer, 255 
Receiver pieces, moulds for telephone, 285 
Regrinding of milling cutters, 231 
Relation of broaching to sheet-metal work, 267 
Reproduction, the great principle of, 29 
Rolling of seams, 446 
Rose reamers, taper of, 257 
Rotary swaging machines, 485 
Rough castings in pairs, drilling, 74 
Round bodies, machine for double-seaming, 442 

drill tables, machining, 222 
Rubber, cutting soft, 506 

grinding, 506 

turning and truing, 505 



532 INDEX. 



SAND-BLASTING of milling cutters, 242 
Screw, cutting coarse-pitch, 304 

machine, method for finishing duplicate work in, 195 

special tools for, 190 

tools and fixtures for speed indicators, 193 
Seaming bottoms with burred edges, 441 

double horning and, 443 

horning process and, 440 

petroleum cans, 445 
Secrets of working aluminum, 493 
Selecting a set of milling cutters, 239 
Set of jigs for milling and drilling, 348 

of tools for machining a cam, 300 
Sextet casting, boring and facing fixture for, 209 
Shearing die, 373 
Sheet brass blanks, trimming, 313 

Sheet metal, depth which may be drawn at one operation, 368 
drawing deep shells from, 393 
parts, drawing and forming decorated, 369 
use of, in place of other materials, 365 
work, broaching, its relation to, 267 
Shell and end milling cutters, 234 

bottomless, perforating, 435 

burner, perforating, 434 

cylindrical, perforating, 433 
Side clearance in milling cutters, 228 
Simple dies, making and use of, 371 

drill jigs, 42 

constructing, 43 

drilling jigs and their use, 64 
fourteen-hole, 59 
types of, 55 

lathe chuck, 312 

milling fixtures, 129 

six distinct types of, 129 

slotting fixture, 314 
Simplest class of press tools, 366 
Sinking embossing dies and drop dies, 468-478 
Slolter, small die, 360 

Slotting and dovetailing small castings, milling fixture for, 134 
Small accurate work, drill jig for, 89 

cams, indexing dial jig for, 109 

thread dies, jig for drilling, 325 
Smith, Oberlin, 267 
Soldering aluminum, 499 

face plate, a, 310 

liard-, 507 



INDEX. 53$ 



Some points about broaches and broaching, 265 
Special box tools for screw machine, 190 

cam milling machine, 337 

casting, tools for machining, 180 

chucks for turret-lathe, 170 

designs, perforating large sheets in, 439 

engraving machine, 334 

fixtures in the turret-lathe, use of, 162 

job of tool-making, 331 

machine for accurate work on dies, 355 

for boring drill-press brackets and spindle heads, 214 

milling and drilling jigs, 344 

tools, advantage in the use of, 223 

and fixtures for machining pulleys, 172 
for cutting out large fibre washers, 329 
for the sc-ew machine, 190 
for turret-lathe, 162 

uses of micrometer calipers, 271 
Speed and feed of milling cutters, 239 

indicators, tools and fixtures for, 190 

lathe milling, jig for, 318 

of pulleys and gears, 508 
Spherical moulds, 298 
Spindle racks, milling, 322 

fixture for, 320 
Spring strippers, 379 

winding fixture, 309 
Square reamers, 258 
Squaring holes, die for, 374 

the ends of duplicate pieces, milling fixture for, 132 
Standard types of milling cutters, 226 
Stationary strippers sometimes distort sheets, 379 
Step jig, 307 
Stick, flaking, 311 

Straps, cam for turning eccentric, 340 
Sub-press, 461 

cost vs. longevity of, 463 

dies, action of, 466 

feeding the metal to, 466 

how to construct, 463 

setting and using, 465 

use of, 462 

utility of, 462 

Successful use of milling fixtures, factors in, 141 
Swaging, cold, processes of, 479 

effects of work accomplished by, 491 

machines, horizontal, 489 
rotary, 485 
the Dayton, 487 



534 INDEX. 

T 

TANKS for pickling cast iron, 509 
Taper and crowning shells, perforating, 434 

of rose reamers, 257 

reaming in the screw machine, 256 
Telephone receiver pieces, moulds for, 285 

transmitter cases, compound dies for, 423 
Templets, 31 

Test for hardness of cutters, 242 

Testing lathe centres for height with micrometer calipers, 272 
The hammer, 479 

height-gauge and its use, 274 

most skilled mechanic in the world, 26 
Tinning cast iron, 509 
Tool-holders, patent, 507 
Tool-maker's lathe, 36-37 
Tool-making, milling machine and modern, 120 

unusual job of, 331 
Tool-rooms, and their equipment, 36 

Brown and Sharpe, 39 

milling machines in, 125 
Tools for screw machine, special, 190 

for speed indicators, screw machine, 193 
Trimming sheet-metal blanks, 313 

Triple-action die for blanking, drawing, and embossing, 410 
Turret-lathe, attachment for forming irregular pieces from the bar, 163 

box tool for, 160 

multi-spindle drilling and tapping fixture for, 183 

set of tools for machining pulleys in, 172 

special tools for, 162 

tools for machining a special casting in, 180 

two special chucks for, 170 

use of special device for, 190 

special fixtures in, 162 

Twentieth-century manufacturing, ideal, 513 
Twist -drill, 245 

grinding for cutting section of hole, 505 
Twisting corkscrews, 327 
Two-nose chucks for eccentric cams, 340 
Types of very simple milling fixtures, six distinct, 129 

very simple drilling jigs, 55 
Typewriter bases, drill jig for, 85 

U 

UNDERCUT teeth, milling cutters with, 226 

Universal equipment vs. working-range equipment, 515 

milling machines, 122 
Up-to-date fixtures and machine tools, 512 



INDEX. 535 



Up-to-the-minute machines and tools, 512 
Use and abuse of milling cutters, 230 

and construction of boring fixtures, 208 

of brass-working tools, 503 

of modeller's wax, making and, 473 

of micrometer calipers, 268 

of milling fixtures, factor in the successful, 141 

machines, 120 

of power-presses, progress in, 355 
of sheet metal in place of other materials, 365 
of special fixtures in the turret-lathe, 162 

tools, advantage in the, 223 
Utility of milling machines, 120 

doubt of, 128 
of the sub-press, 462 

V 

VALUE of up-to-date fixtures and machine tools, 512 

Vertical spindle milling machines, 127 

Vital point in milling-machine practice, most, 236 

W 

WATER or fluid dies, 474 
Way to construct a drawing die, 370 

to keep note-books of shop practice, 511 
Whitney, Eli, 19 
Wiring and curling processes, 474 

straight work, 448 
Working aluminum, 493 

Working-range equipment vs. universal equipment, 515 
Workman's supplies, 39 
Work not to be jigged, 34 



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