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In mid-July, we received an inquiry from a domestic customer for stainless steel 304 & 316 seamless pipes. The customer had specific specifications, wall thickness, and tolerances, and hoped we could offer competitive pricing while ensuring quality. Upon receiving the inquiry, we immediately provided detailed technical information and a quotation, promising on-time delivery to ensure the smooth progress of the project.

Product List

ITEM	DESCRIPTION	QUANTITY	UNIT
1	12mm×1.25 SS316 GB/T14976	72	M
2	26.7mm×2.87 A312-TP316 ASME B36.19 SCH40S	12	M
3	42.2mm×3.56 A312-TP316 ASME B36.19 SCH40S	6	M
4	48.3mm×3.68mm A312-TP316 ASME B36.19M SCH40S	6	M
5	60.3mm×3.91mm A312-TP316 ASME B36.19M SCH40S	12	M
6	114.3mm×6.02mm A312-TP316 ASME B36.19M SCH40S	6	M
7	21.3mm×3.73mm A312-Gr.TP316L ASME B36.19M SCH80S	6	M
8	26.7mm×2.87 A312-TP304/304L ASME B36.19 SCH40S	6	M
9	33.4mm×3.38 A312-TP304/304L ASME B36.19 SCH40S	6	M

Dimensional Inspection of Stainless Steel Pipes

The inspection process typically uses tools such as vernier calipers, outside micrometers, wall thickness gauges, and steel tape measures to perform spot checks or full inspections of each pipe.

Outer Diameter Measurement: Measure the outside diameter at both ends and in the middle of the pipe to ensure that the deviation is within the standard tolerance.

Wall Thickness Measurement: Use an ultrasonic wall thickness gauge or micrometer to measure the wall thickness at various locations to prevent uneven wall thickness from affecting performance.

Length Measurement: Use a steel tape measure to measure the total length or cut length of the pipe to ensure it meets contractual requirements.

End Face Inspection: Verify that the cut end of the pipe is smooth and free of visible burrs or cracks.

ASTM A312 TP304 & 316 Pipe 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 TP304 & 316 Pipe 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 304 & 316 Seamless Pipes Physical Property

Grade	Density(kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C(J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100°C	0-315°C	0-538°C	at 100°C	at 500°C
304/L/H	8000	193	17.2	17.8	18.4	16.2	21.5	500	720
316/L/H	8000	193	15.9	16.2	17.5	16.3	21.5	500	740

Stainless Steel 304 Seamless Pipe

304 stainless steel seamless pipes are known as “general-purpose stainless steel” due to their excellent corrosion resistance, good machinability, and relatively affordable price.

Chemical Composition: Contains approximately 18% chromium and 8% nickel (hence often referred to as 18/8 stainless steel).

Corrosion Resistance: Performs well in most non-chloride environments and effectively resists everyday corrosion.

Hot and Cold Working Properties: Exhibits excellent formability and weldability, making it easy to process into various shapes.

Application Areas: Widely used in food processing equipment, kitchenware, medical devices, architectural decoration, and general chemical piping, among others.

Stainless Steel 316 Seamless Pipe

316 stainless steel seamless pipes, which contain added molybdenum (Mo), offer superior corrosion resistance compared to 304.

Chemical Composition: Contains approximately 16% chromium, 10% nickel, and 2-3% molybdenum.

Corrosion Resistance: The addition of molybdenum significantly enhances its corrosion resistance in chloride environments, effectively resisting pitting corrosion and crevice corrosion.

Application Areas: It is the preferred material for marine environments, chemical industries, papermaking industries, pharmaceutical equipment, and coastal facilities, and is commonly referred to as “shipbuilding steel.”

Stainless Steel Pipes Dimension

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

ASTM A312 TP304 & 316 Stainless Steel Pipes Applications

Food processing equipment, particularly in beer brewing, milk processing & wine making.

Kitchen benches, sinks, troughs, equipment and appliances

Architectural panelling, railings & trim

Chemical containers, including for transport

Heat Exchangers

Woven or welded screens for mining, quarrying & water filtration

Threaded fasteners

Springs

14 8 月, 2025