Metallurgy Of Cast Iron

FIG. 114.—CHILL PIG MOULD AND CASTING.
FIG. 115,—CROSS SECTION OF SMALL AND LARGE CHILL PIG MOULDS.
FIG. 116.—LONGITUDINAL SECTION OF CHILL PIG MOULD. 115 and 116, is graduated on one side, as shown, to measure the contraction in the sixty-fourths of an inch. The rule is cut off on the small end at a point where it is one-sixteenth of an inch in thickness. From this the taper runs up two inches, at which point it measures three-sixteenths of an inch. The distance between the one-sixteenth and three-sixteenths points is then equally divided by six lines, as shown, so as to read to the one-sixty-fourth part of an inch, according as the space of contraction will permit the rule to be inserted between the chill-mould and the pig specimen, as shown. The lines being one-quarter of an inch apart, the scale can be easily read; but the rule could, of course, be graduated finer if desired.