12-INCH STEEL B. L. RIFLES
50
Jacket.
No. 7364.
־\ x 1	12 R50 J
Marks, m t, o Diameter, ".564.
Sectional area, .25 square inch. Gauged length, 3".
Applied loads per square inch.	Elongation per inch.	Successive elongation per inch.	Permanent set.	Successive permanent set.	Remarks.
Pounds. 1,000 5,000 10,000 20,000 30.000 35.000 40.000 42.000 51.000 52.000 53.000 54.000 55.000 56.000	Inch. 0. .000100	Inch. 0. .000100 .000200 .000333 .000367 .000133 .000200 .000100 .000300 . 000934 .001666 .005000 .000334 .000400	Inch. 0. 0.	Inch. 0. 0.	Initial load.
				 1		
					
	.001133		0.	0.	
	.001433		0.	0.	Elastic limit.
					
					
					
					
					
					Tensile strength.
							——.			
General summary.
.........pounds..	88,720
............do...	51,000
...........inch..	.2300
......do... .001733
...........do...	.184
................. 54.6
at the middle of the stem
..........fine silky
........... 12,».43*,"14
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
TABULATION OF STEEL TENSION SPECIMENS FROM 12-IN Oil B. L.
RIFLES.
STEMS OF SPECIMENS, 3" LONG, ".564 DIAMETER.
No. of test.	» Position in gun.	Location of specimens.	Elastic limit per square inch.	Tensil strength per square inch.	Elon- ga- tion.	Contraction of area.	Appearance of fracture.	Remarks.
7283 7362 7363 7252 7355 70-24	Tube — ...do	 ...do	 Jacket... ...do	 ...do		Middle . ...do	 ...do	 ...do — ...do — Outside.	Pounds. 49.000 45.000 44.000 51.000 48.000 51.000	Pounds. 91.360 87,120 81,200 100,640 94.360 88,720	Pr. ct. 21.0 22.3 24.7 20.3 23.3 23.0	Pr. ct. 41.9 41.9 47.2 39.2 44.6 54.6	Silky	 	do	 	do	 	do	 	do	 Fine silky		Muzzle end. Breech end. Muzzle end. Breech end. Muzzle end. Do.