165
OUTER BASES---15-POUNDER GUN MOUNTS,
No. 7240.
Marks, 20B15 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.	Initial load.
5,000	.00010	.00010	0.	0.	
10,000	.00025	.00015			
20,000	.00070	.00045			
21,000	.00075	.00005			
22,000	.00085	.00010			Elastic limit.
23,000	.00110	.00025			
24,000	.00165				
25,000	.00245	.00080			
26,000	.00375	.00130			
27,000	.00500	.00125			
28,000	.00610	.00110			
63,400					Tensile strength.
					
General summary.
Tensile strength per square inch of original section.................... pounds 63 -1011׳
Elastic limit per square inch of original section... do ” 22000 ׳
Elongation per inch after rupture................... ' inch 2050
Elongation per inch under strain at elastic limit........... .................. do "" 00085
Reduction in diameter at point of rupture......................................".".do!!!	.065
Reduction in area after rupture, per cent of original section....... ................... 23 9
Position of rupture............................................................ 95.״ from n“e¿¿
Character of broken surface......................... dull silky 80 per cent, granular 20 per cent
Elongation of inch sections....................................................... 20,« *21.״
No. 7213.
Marks, ob is 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 29.000 30.000 31.000 32.000 33.000 34.000 46,300	Inch. 0. . 00010 .00030 .00065 .00100 .00790 .00865 .00950 .01040 .01150	Inch. 0. .00010 .00020 . 00035 .00035 .00690 . 00075 .00085 .00090 .00110	Inch. 0. 0.	Inch. 0. 0.	Initial load. Elastic limit. Tensile strength.
					
					
					
					
					
					
					
					
					
General summary.
Tensile strength per square inch of original section..................... pounds 46 300
Elastic limit per square inch of original section.................. do * ’ 29 000
Elongation per inch after rupture.................................. ............inch” 0500
Elongation per inch under strain at elastic limit..................I * do ” 00100
Reduction in diameter at point of rupture..................... ..................do"""	005
Reduction in area after rupture, per cent of original section............................18
Position of rupture............................................................. 20.״ from neck
Character of broken surface... dull gray amorphous in part, and in part granular; irregular surface Elongation of inch sections.....................................................mmm ״Qg 07,״*