HAVIOUR OF MATERIALS IN TESTING MACHINE 185 
The specimens were turned to the forms and dimensions shown in 
258 and 259. 
———— - 3% Ms eel a ee 
’ « AT, 
564 “564 
i t 
- - = - 24-- + = = 214 - - rite 1" 
Fig. 258. Fia. 259. 
_ The next table shows the results of tests on specimens turned out of 
rolled bars }# inch diameter. These rolled bars were made as follows. 
Billets 3 inches in diameter and about 20 inches long were cast in 
_ cast-iron moulds. These billets were first turned in a lathe, and the 
diameter thus reduced to 21% inches. They were then heated to 
about 800° C. (1472° F.) and rolled down, first to 14 inches diameter, - 
and then to +$ inch diameter. The gauge length of the specimens 
was 2 inches. 
Yield- Ultimate Elongation Reduction — 
Alloy, | Aluminium. Pics Stress. on 2 inches. of Area. Cubic 
; : : oot. 
No. Per cent gt bg my Per cent. Per cent. Lbs. 
1 0°10 6°9 14°50 65°5 90°71 556 
eo 1:06 69 15°88 61:0 88°63 548 
3 2°10 8°6 17°46 56°5 89°65 537 
4 2°99 116 19°79 57:2 86°11 528 
5 4°05 11:3 23°80 67:0 83°27 518 
6 5°07 11°4 26°41 69°2 77°80 510 
7 5:76 11°8 28°40 742 76°93 503 
8 673 10°4 28°85 71:0 75°02 499 
ae 735 10°6 29°68 725 74:34 492 
10 8:12 13°0 33°22 51°5 60°40 487 
il 8°67 1l‘1 36°67 38:0 50°66 482 
12 9°38 177 . 38°00: 34:0 33°60 477 
13 9°90 14:8 38°10 28°8 30°80 473 
14 10°78 15°4 38°62 14-0 18°60 466 
15 11:73 12°6 33°85 85 15°37 460 
16 13°02 st. 87°14 20 1°87 451 
_ __ Fig. 260 shows stress-strain diagrams taken from longer specimens 
4 eee from the +2-inch rolled bars. The parallel portion was 10°5 
inches long and 0°564 inch diameter, and the gauge length was 8 inches. 
_ The numbers on the curves are the descriptive numbers of the alloys. It 
_ will be observed that the various diagrams are displaced to the right, so 
_ that the zero points of elongation are at the points showing the percentage 
_ of aluminium in the respective alloys. 
