13
3.6-INCH B. L. FIELD MORTARS Bodies.
Marks.	Diam- eter.	Sec- tional area.	Elastic limit per square inch.	Tensile strength per square inch.	Elon- gation.	Contraction of area.	Appearance of fracture.	Elongation of inch sections.	
2	Inch. .505	Sq.inch. .20	Pounds. 63,000	Pounds. 100,600	Per ct. 18.5	Per ct. 40.3	Silky, 60 per cent; gran-	// . 9.7*	// .10
3	.505	.20	63,000	107,500	16.0	34.0	ular, 40 per cent. Silky, 40 per cent; gran-	.15,	.17*
4	.505	.20	57,500	96,950	18.5	43.3	ular, 60 per cent. Silky		.10,	
5	.505	.20	64,000	108,100	19.5	37.1		do		.14,	.25*
6	.505	.20	53,500	87,600	21.5	49.1		do		.11,	
7	.505	.20	57,000	99,750	18.5	37.1		.09,	.28*
8	.505	.20	57,500	103,500	17.5	30.7	Silky, 30 per cent; gran-	.10,'	.25*
9	.505	.20	54,000	98,250	20.5	30.7	ular, 70 per cent. Silky, 15 per cent; gran-	.19,	.22*
10	.505	.20	57,000	101,950	19.0	34.0	ular, 85 per cent. Silky, 30 per cent; gran-	.18,	.20*
11	.505	.20	64,000	103,250	19.5	37.1	ular, 70 per cent. Silky, 40 per cent; gran-	.14,	.25*
12	.505	.20	53,500	96,700	19.5	3?.l	ular, 60 per cent. Silky, 60 per cent; gran-	.12,	.27*
13	.505	.20	54,000	106,600	18.0	27.4	ular, 40 per cent. Granular, silky spot at	.14,	.22*
14	. 505	.20	58,500	108,250	16.0	27.4	circumference. Granular, 80 per cent;	.10,	.22*
15	. 505	.20	60,000	111,500	17.0	27.4	silky, 20 per cent. Granular, 70 per cent;	.14,	.20*
16	.505	.20	56,500	94,500	19.5	46.2	silky, 30 per cent. Silky		.09,	.30*
17	.505	.20	57,500	106,500	17.5	30.7	Granular, 40 per cent:	.23*,	.12
L	.564	.25	54,400	103,000	25.0	57.0	silky, 60 per cent, oblique. Silky, serrated«		.21,	.29*
T	. 564	. 25	59,200	100,320	18.5	39.2	Granular, silky center«.	.10,	.27*
Breechblocks.
//	n
10,	.25*
10,	.27
25*,	.10
31*,	.14
08,	.21*
Silky, 80 per cent; fine granular, 20 per cent.
Silky, oblique........
Silky serrated, 85 per cent; granular, 15 per cent.
Silky, cup-shaped......
Sil ky, 60 per cent; granular, 40 per cent.
1	.505	.20	60,500	98,800	17.5	34.0
2	.505	.20	61,200	98,400	18.5	34.0
3	.505	.20	74,750	102,350	17.5	34.0
4	.505	.20	65,000	106,000	22.5	49.1
5	.505	.20	61,000	100,600	14.5	34.0
Obturating Spindles.
1	.564	.25	73,600	98,000	22.0	61.5	Fine silky		// // II . 22,. 37*,. 09
2	. 564	.25	62,720	85,680	25.7	61.5		do		. 16,. 46*,. 15
3	. 564	.25	58,520	83,760	23.7	67.8		do		. 22'. 40, '. 09
1	.505	.20	69,000	112,050	19.0	46.2	Silky		*28. ,׳10.
2	.505	.20	60,500	112,700	18.5	46.2		do		.28* . 09
3	.505	.20	68,000	109,500	21.5	51.9		do		.30* . 13
4	.505	.20	64,750	107,500	19.5	40.3		do		.14, .25*
5	.505	.20	69,900	110,100	21.5	51.9		do		.10', .33*
Gas Checks.
		//	//
39.2	Granular, silky center..	.11,	.27*
15.0	Fine granular		.12*,	.05
30.7	Silky, 10 per cent; fine granular, 90 per cent.	.07,	.23*
51.9	Silky, 20 pei cent; fine granular, 80 percent.	.10,	.33*
20.5	Fine granular, silky spot at center.	.07,	.15*
	.564	.25	66,400	114,320	19.0
	.564	.25	ftl20,000	145, 600	8.5
1	c. 505	.20	57,500	116,950	15.0
2	d. 505	.20	62,000	109,000	21.5
	.505	.20	81,000	150,000	11.0
d Same, oil treated.
c Natural state of steel.
ft Approximate.
Forgings, from billet.