171
OUTER BASES---15-POUNDER GUN MOUNTS.
No. 7245.
Marks, OB is Diameter, ".505.
Sectional area, .20 square inch. Gauged length, 2".
Initial load.
Elastic limit.
Tensile strength.
Elongation per inch.	Successive elongation per inch.	Permanent set.	Successive permanent set.
Inch. 0. . .00010 . 00025 .00055 .00075 .00090 .00095 . 00500 .00590 . 00660 . 00725 . 00810	Inch. 0. .00010 .00015 .00030 .00020 .00015 .00005 .00405 .00090 .00070 .00065 . 00085	Inch. 0. 0.	Inch. 0. 0.
			
			
			
			
			
			
			
			
			
			
			
Applied loads per square inch.
Pounds. 1,000 5,000 10,000 20,000
25.000
28.000
29.000
30.000
31.000
32.000
33.000
34.000 71,400
General summary.
.....................pounds..	71,400
........................do...	29,000
.......................inch..	.0800
.........................do...	.00095
.........................do...	.025
............................. 9.5
......................"54 from neck
granular, silky spot at circumference .......................... ".	07,	09*
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.............................
No. 7270.
Marks, 2o6bi5 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 72.000	Inch. 0. .00010 .00035 .00065 ‘. 00105 .00110 .00130 . 00150 .01040 .01145 .01200	Inch. 0. .00010 .00025 . 00030 .00040 . 00005 .00020 .00020 .00890 . 00105 . 00055	Inch. 0. 0.	Inch. 0. 0.	Initial load. Elastic limit. Tensile strength.
					
					
					
					
					
					
					
					
					
					
General summary.
......................pounds..	72,000
..........................do...	32,000
.........................inch..	.1850
.........................do...	.00110
.........................do...	.065
............................... 23.9
...................... ".75 from neck
granular 60 per cent, silky 40 per cent ...........................".20*, ".17
'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.............................