173
OUTER BASES---15-POUNDER GUN MOUNTS.
No. 7275.
Marks, o b*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.	Inch.	Inch.	Inch.	Inch.	
1,000	0.	0.	0.	0.	
5,000	. 00010	.00010	0.	0.	
10,000	. 00030	.00020			
20,000	. 00060	.00030			
30,000	. 00105	.00045			
31,000	.00115	. 00010			Elastic limit.
32,000	.00150	. 00035			
33,000	.00815	.00665			
34,000	.00855	. 00040			
35,000	. 00930				
36,000	. 01025	. 00095			
72,600					Tensile strength.
General summary.
.....................pounds.. 72,600
.........................do... 31,000
........................inch.. .1400
.........................do... .00115
.........................do...	.045
.............................. 16.9
■...................... ".7 from neck
granular 60 per cent, silky 40 per cent
*15.״ ,13.״ ........................
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. 72S8.
Marks, ob°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.	Inch.	Inch.	Inch.	Inch.	
1,000	0.	0.	0.	0.	
5,000	.00010	.00010	0.	0.	
10,000	.00035	.00025			
20,000	.00060	.00025			
30,000	. 00100	.00040			
36,000	. 00120	. 00020			
37,000	.00130	.00010			Elastic limit.
38,000	.00710	.00580			
39,000	.00750	. 00040			
40,000	. 00845	.00095			
41,000	. 00895	. 00050			
42,000	. 00975	.00080			
85,100					Tensile strength.
General summary.
......................pounds..	85,100
.........................do...	37,000
........................inch..	.1500
.........................do...	.00130
.........................do...	.045
.............................. 16.9
....................... ".6 from neck
granular 70 per cent, silky 30 per cent .......................... ".16*, ".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.......................