152	INNER BASES---15-POUNDER GUN MOUNTS.
No. 7280.
Marks, ib°i5 Diameter, ".505.
Sectional area, .20 square inch. Gauged length, 2".
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 32.000 33.000 34.000 35.000 36.000 37.000 74,100	Inch. 0. .00010 . 00035 .00060 . 00100 .00105 . 00750 .00835 . 00900 . 01000 .01100	Inch. 0. .00010 .00025 .00025 . 00040 . 00005 .00645 .00085 .00065 .00100 .00100	Inch. 0. 0.	Inch. 0. 0.	Initial load. Elastic limit. Tensile strength.
					
					
					
					
					
					
					
					
					
					
General summary.
......................pounds..	74,100
.........................do...	32,000
........................inch..	.1600
.........................do...	.00105
.........................do...	.045
.............................. 16.9
..................... ".75 from neck
granular 80 per cent, silky 20 per cent ..........................18*, ". 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............................
7281.
Marks, i b !5•
Diameter, ".505.
Sectional area, .20 square inch. Gauged length, 2".
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 . 32,000 33.000 34.000 35.000 36.000 37.000 73,800	Inch. 0. .00010 .00030 .00060 . 00095 .00105 .00825 .00850 .00880 .00945 .01060	Inch. 0. .00010 .00020 . 00030 . 00035 .00010 . 00720 .00025 .00030 .00065 .00115	Inch. 0. 0.	Inch. 0. 0.	Initial load. Elastic limit. Tensile strength.
					
					
					
					
					
					
					
					
					
					
General summary.
Tensile strength per square inch of original section.............................pounds.. 73,800
Elastic limit per square inch of original section.................................do... 32,000
Elongation per inch after rupture................................................inch.. . 1850
Elongation per inch under strain at elastic limit.................................do... . 00105
Reduction in diameter at point of rupture.........................................do...	.055
Reduction in area after rupture, per cent of original section............................ 20.5
Position of rupture.............................................................. ".75 from neck
Character of broken surface............................ granular 60 per cent, dull silky 40 per cent
Elongation of inch sections....................................................... ".15, ".22*