ASTM A312 Stainless steel pipe is a hollow long cylindrical steel, usually used as a pipeline for conveying fluids, and is widely used in industrial fields such as petroleum, chemical, medical, food, light industry, mechanical instruments, etc.

ASTM A312 Standard

This specification covers seamless, straight-seam welded, and heavily cold worked welded austenitic stainless steel pipe intended for high-temperature and general corrosive service.

Grades TP304H, TP309H, TP309HCb, TP310H, TP310HCb, TP316H, TP321H, TP347H, and TP348H are modifications of Grades TP304, TP309Cb, TP309S, TP310Cb, TP310S, TP316, TP321, TP347, and TP348, and are intended for high-temperature service.

Table X1.1 lists the standardized dimensions of welded and seamless stainless steel pipe as shown in ANSI B36.19. These dimensions are also applicable to heavily cold worked pipe. Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification.

Specification of Stainless Steel Pipe

Processing Method	Seamless and Welded
Size Range	1/8” – 30” / DN6 – 750
Thickness Schedule	SCH 10S- SCH 160, XXS
Length	6m or 12 m or Random
Standard	ASME B36.19M,ASME B36.10M
Surface Treatment	Polish , Mirror , Epoxy Powder FBE, 2PE, 3PE Coating
Material Grade	ASTM A312 TP304/304L/304H, 316/316L, 310S, 317, 347, 904L, S32205, S31803, 32750, 32760, S32550

ASTM A312 Material Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Ni	Cr	Mo
ASTM A312 TP304	MIN						8.00	18.00
	MAX	0.08	2.00	0.05	0.03	1.00	11.00	20.00
ASTM A312 TP304L	MIN						8.00	18.00
	MAX	0.035	2.00	0.045	0.030	1.00	13.00	20.00
ASTM A312 TP316	MIN						11.00	16.00	2.00
	MAX	0.080	2.00	0.045	0.030	1.00	14.00	18.00	3.00
ASTM A312 TP316L	MIN						10.00	16.00	2.00
	MAX	0.035	2.00	0.045	0.030	1.00	14.00	18.00	3.00

ASTM A312 Material Mechanical Property

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %
ASTM A312 TP304	515min	205 min	35 min
ASTM A312 TP304L	485 min	170 min	35 min
ASTM A312 TP316	515min	205min	35 min
ASTM A312 TP316L	485 min	170 min	35 min

Stainless Steel Pipe Dimension

ASTM A312 TP304 stainless steel pipe is a general purpose stainless steel pipe used in different industries. Its diameter ranges from 1/8” to 30”, and thickness ranges from SCH 5S to SCH 80S.

Stainless Steel Pipe (ASME B 36.19M)
Nominal Size		OD	Sch5s		Sch10s		Sch40s		Sch80s
DN	NPS	0	T	kg/m	T	kg/m	T	kg/m	T	kg/m
6	1/8	10.3			1.24	0.28	1.73	0.37	2.41	0.47
8	1/4	13.7			1.65	0.49	2.24	0.63	3.02	0.8
10	3/8	17.1			1.65	0.63	2.31	0.84	3.2	1.1
15	1/2	21.3	1.65	0.82	2.11	1	2.77	1.27	3.73	1.62
20	3/4	26.7	1.65	1.04	2.11	1.28	2.87	1.69	3.91	2.2
25	1	33.4	1.65	1.33	2.77	2.09	3.38	2.5	4.55	3.24
32	1 1/4	42.2	1.65	1.68	2.77	2.7	3.56	3.39	4.85	4.47
40	1 1/2	48.3	1.65	1.95	2.77	3.11	3.68	4.05	5.08	5.41
50	2	60.3	1.65	2.44	2.77	3.93	3.91	5.44	5.54	7.48
65	2 1/2	73.0	2.11	3.77	3.05	5.26	5.16	8.63	7.01	11.41
80	3	88.9	2.11	4.6	3.05	6.45	5.49	11.29	7.62	15.27
90	31/2	101.6	2.11	5.29	3.05	7.4	5.74	13.57	8.08	18.63
100	4	114.3	2.11	5.96	3.05	8.36	6.02	16.07	8.56	22.32
125	5	141.3	2.77	9.67	3.4	11.57	6.55	21.77	9.53	30.97
150	6	168.3	2.77	11.55	3.4	13.48	7.11	28.26	10.97	42.56
200	8	219.1	2.77	15.09	3.76	19.96	8.18	42.55	12.7	64.64
250	10	273.1	3.4	23.08	4.19	27.78	9.27	60.31	12.7	96.01
300	12	323.9	3.96	31.89	4.57	36	9.53	73.88	12.7	132.08
350	14	355.6	3.96	35.06	4.78	41.3
400	16	406.4	4.19	42.41	4.78	47.29
450	18	457.2	4.19	47.77	4.78	53.26
500	20	508	4.78	60.46	5.54	68.61
550	22	558.8	4.78	66.57	5.54	75.53
600	24	609.6	5.54	84.16	6.35	94.45
750	30	762	6.35	120.72	7.92	147.36

Stainless steel Pipe Permitted Tolerance in Wall Thickness

Tolerance,%from Nominal
NPS Designator	Over(+)	Under (-)
1/8 to 21/2 incl.,all t/D ratios	20.0	12.5
3 to 18 incl.,t/D up to 5% incl.	22.5	12.5
3 to 18 incl.,t/D>5%	15.0	12.5
20 and larger,weldedall t/D ratios	17.5	12.5
20 and larger,seamlesst/D up to 5% incl.	22.5	12.5
20 and larger,seamlesst/D>5%	15.0	12.5
t = Nominal Wall ThicknessD = Ordered Outside Diameter

A312 Pipe Manufacturing Types

ASTM A312 Stainless steel pipe covers following manufacturing types (Including hot finished or cold finished):

a. Seamless Pipe (SMLS): It covers stainless steel seamless pipe that manufactured in any process that can not be involved in the welding process.

b. Welded Pipe (WLD): It covers welded pipe that manufactured by an automatic welding process that does not add filler metal during welding.

c. Cold Worked Pipe (HCW pipe): Heavily cold-worked (HCW) pipe shall be made by applying cold working of not less than 35 % reduction in thickness of both wall and weld to a welded pipe prior to the final anneal. No filler shall be used in making the weld.

d.  Welded pipe and HCW pipe of NPS 14 and smaller shall have a single longitudinal weld.