643
METAL FROM ROTATING SHAFTS
No. 7382.
Marks, '91
Endurance test No. 318. See Report 1900, p. 1134. Diameter, ".564.
Sectional area, .25 square inch.
Gauged length, 3".
Remarks.
Applied loads per square inch.	Elongation per inch.	Successive elongation per inch.	Permanent set.	Successive permanent set.
Pounds. 1,000 5,000 10,000 20,000 30.000 40.000 48.000 49.000 50.000 51.000 52.000 53.000 54.000 55.000 56.000 58, 000 60.000 64.000 68, 000 72.000 76.000 80.000 84.000 88, 000 92.000 94,320	Inch. 0. .000100	Inch. 0. . 000100	Inch. 0.	Inch. 0.
	.000333	.000233		
	.000667	.000334		
	.001000	.000333		
	.001367 .001667	.000367 . 000300	0.	0.
	.001700	.000033		
	.001767 .001900	.000067 . 000133	.000067	. 000067
	.002033	.000133		
	.002167	.000134		
	.002300	. 000133		
	.002400 . 002633	. 000100 .000233	.000400	. 000333
	. 004000	.001367		
	. 008000	. 004000		
	.012167	.004167		
	.016667	.004500		
	.022667	.006000		
	. 028333	. 005666		
	.037	.009		
	.050	.013		
	.063	.013		
	.097	.034		
				
				
Initial load.
Elastic limit (not well defined).
Tensile strength.
General summary.
Tensile strength per square inch of original section...........................pounds..	94,32C
Elastic limit per square inch of original section (not well defined)..............do...	49,000
Elongation per inch after rupture................................................inch..	. 2467
Elongation per inch under strain at elastic limit...............................do...	. 001700
Reduction in diameter at point of rupture.........................................do...	. 204
Reduction in area after rupture, per cent of original section............................ 59.3
Position of rupture............................................................. l". 3 from neck
Character of broken surface.............................................fine silky, cup shaped
Elongation of inch sections.....................................................".13,". 34*,", 27
TABULATION OF TESTS OF SPECIMENS TAKEN FROM THE OUTER ENDS OF SHAFTS WHICH WERE RUPTURED BY REPEATED STRESSES.
Endurance test No.	Diam- eter.	Sec- tional area.	Elastic limit per square inch.	Tensile strength per square inch.	Elongation in 3 inches.	Contraction of area.	Appearance of fracture.	Elongation of inch sections.
304	Inches. .564	Sq.inch. .25	Pounds. 44,000	Pounds. 62,000	Per cent. 33.3	Per cent. 61.5	Fine, silky ....	// tt // .22, .56*,.22
305	.564	.25	58,000	117,400	13.3	21.4	Granular		.19*, .12, .09
306	.564	.25	49,000	82,000	27.3	54.6	Fine, silky		.17, .43*,.22
307	.564	.25	48,000	71,520	30.0	59.3		do		.18, .44*,.28
311	.564	.25	59.000	85,360	26.3	59.3		do		.21, .43*,. 15
317	.564	.25	65,000	91,040	24.3	61.5		do		.13, .30*, .30*
318	.564	.25	49,000	־ 94,320	24.7	59.3		do		.13, .34*, .27*