RIFLE-BARREL STEEL, .30 CALIBER.
72
No. 7393.
Marks, M 3 A.
Sectional area, .25 square inch. Gauged length, 1".
From butt of finished barrel.
Rolled and annealed as usual.
Remarks.
Initial load.
Elastic limit.
Tensile strength.
Permanent set.	Successive permanent set.
Inch. 0.	Inch. 0.
	
	
	
	
	
0.	0.
	
	
	
	
	
	
	
	
	
	
	
	
	
Successive elongation per inch.
Elongation per inch.
Inch.
0.
.0002 . 0002 .0003 .0003 .0004 .0004 .0004 .0004 . 0025 .0014 .0010 .0018 . 0042 . 0052 .0043 . 0062 .011 .01 .01
Inch.
0.
.0002 .0004 .0007 .0010 .0014 .0018 . 0022 .0026 .0051 . 0065 .0075 .0093 .0135 .0187 . 0230 . 0292 .04 .05 .06
Applied loads per square inch.
Pounds. 1,000 5,000 10,000 20,000
30.000
40.000
50.000
60.000
68,000
69.000
70.000
71.000
72.000
76.000
80.000
84.000
88.000
92.000
95.000 100,000 108,160
General summary.
.pounds.. 108,160
....do... 68,000
___inch.. .26
....do...	.0026
.silky, cup-shaped
Tensile strength per square inch of original section
Elastic limit per sauare inch of original section.
Elongation per inch after rupture.................
Elongation per inch under strain at elastic limit— Character of broken surface.......................