Metallurgy Of Cast Iron

STRENGTH IN SPECIALTY MIXTURES.
No. 41 stood 6,000 pounds; No. 43 stood a pull of 19,000 pounds, and No. 47 separated at 21,120* pounds.
TABLE 04.—TRANSVERSE TESTS OF STOVE PLATE IRON.
« 4J H 6 fc Common rule measurement. Microm't'r measurement. Deflection. Broke at in pounds. Strength per square inch in pounds.
51 Rough bars. y% in square 475 in 220 in r 60 711 1,280
52 53 .476 " •474 " .260 " .250 " 170 i. SO 747 1,360 669 1,200
Rough bars, i in square 994 in. 150 in. i 757 1,778 . .
55 •975 " .160 " i,747 ......
56 Rough bars. i54 in- diam .118 in. .170 in. 1,780 i, SIT ......
57 .126 " .170 " 1.775 1:3*3 ......
58 Turned bars. il/z in. diam .......... .127 in. .180 in. 1,320 1,322 ......
59 60 .140 " .125 " .180 " .180 " 1,440 1,335 1,412 ...... 1,343 ......

Test bars furnished by Bissell & Co., Allegheny, Pa. Tested by J. B. Nau, at the works of McConway & Torley, June aoth, 1894. Witness, R. G. G. Meldenke, E. M., Ph. D.
The above tests of the inch square and round bars assert this iron to be of good strength for the work, intended. A factor in this series which will no doubt attract attention is the light load the half-inch bar stood in comparison with the larger sizes and only goes to further demonstrate the erratic and deceptive results which we may expect with small test bars. No. 53 stood 6,000 pounds tensile; No. 54 stood 16,600 pounds; and No. 60 stood 17,150 pounds.
In studying Table 95, one is impressed with the uniformity of the load the bars stood and also the weight necessary to break them, for as a general thing 1' white iron '' exhibits little strength in castings. The tests would lead us to decide that the greatest weakening element in castings made of "white iron " is due to excessive contraction, which is characteristic ofA few of these bars were pulled for the tensile strength.hat recording the strongest mixture, seen in Table 89; the