167
OUTER BASES—15-POUNDER GUN MOUNTS.
No. 7217.
Marks, obis 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	Inch. 0. .00010 . 00020	Pick. 0. .00010 .00010	Inch. 0. 0.	Inch. 0. 0.	Initial load.
20,000	.00060	.00040			
30,000	.00100	.00040			
31,000	.00105	.00005			
32.000	.00110	.00005			Elastic limit.
33,000	.00800	.00690			
34,000	.00835	.00035			
35,000	.00865	. 00030			
36,000	. 00955	.00090	1		
37,000	. 01040	.00085			
74,400					Tensile strength.
					
General summary.
......................pounds..	74,400
..........................do...	32,000
.........................inch..	.1500
..........................do...	.00110
.........................do...	.045
............................... 16.9
...................... ".48 from neck
granular 85 per cent, silkv 15 per cent ...........................".17*, ".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. 7218.
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.	Remark*.
Pounds.	Inch.	Inch.	Inch.	Inch.	
1,000	0.	0.	0.	0.	Initial load.
5.000	.00015	.00015	0.	0.	
10,000	.00030	.00015			
20,000	.00065	.00035			
25,000	.00085	.00020			
27,000	.00095	00010 ״			
28,000	.00100	.00005			Elastic limit.
29,000	.00515	.00415			
30,000	.00590				
31,000	.00660	.00070			
32,000	. 00750	.00090			
33,000		.00125			
34,000	.00935	.00060			
71,500					Tensile strength.
General summary.
......................pounds..	71,500
.........................do...	28,000
.........................inch..	.1100
.........................do...	.00100
.........................do...	.035
............................. 13.2
......................".54 from neck
granular 85 per cent, silky 15 per cent ...........................".12*, ".10
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.............................