12-INCH STEEL B. L. RIFLED MORTARS.
56
Tube.
No. 7402.
Marks, m T5om T Diameter, ".564.
Sectional area, .25 square inch. Gauged length, 3".
Remarks.
Initial load.
Elastic limit.
Tensile strength.
Permanent set.	Successive Permanent set.
Inch. 0. 0.	Inch. 0. 0.
	
	
oo	oo
	
	
	
	
	
	
	
	
Successive elongation per inch.
Inch.
0.
.000100 .000233 .000334 .000333 .000167 .000166 .000334 .000200 .003466 .001100 .001400 .000834 .001333
Applied loads per square inch.	Elongation per inch.
Pounds.	Inch.
1,000	0.
5,000	. 000100
10,000	. 000333
20,000	.000667
30,000	.001000
35,000	. 001167
40,000	. 001333
50,000	.001667
55,000	.001867
56,000	. 005333
57,000	. 006433
58,000	.007833
59,000	.008667
60,000	.010000
92,400	
General summary.
.pounds.. 92,400
____do... 55,000
...inch..	.1967
....do... .001867
____do...	.164
.......... 49.7
... 9.״ from neck ............silky
08." ,13 .״ ,*38 .״ ..
Tensile strength, per square inch of original section...
Elastic limit per square inch of original section.......
Elongation per inch after rupture.......................
Elongation per inch under strain at elastic limit.......
Reduction in diameter at point of rupture...............
Reduction in area after rupture, per cent of original section.
Position of rupture.....................................
Character of broken surface.............................
Elongation of inch sections.............................