ASTM A312 TP304 Material Pipe.PDF

What material is ASTM A312 TP304?

ASTM A312 TP304 is a standard specification for seamless, straight-seam welded, and heavily cold-worked welded austenitic stainless steel pipe. It is commonly known as "18/8" stainless steel, composed of 18% chromium and 8% nickel, designed for high-temperature and general corrosive service environments.

 

What does TP mean in TP304?

In TP304 stainless steel, TP stands for Tube or Pipe. This designation, common in ASTM specifications (such as ASTM A312 or A213), indicates that the material is intended for use as stainless steel tubing or piping, typically for fluid transport or structural applications.

 

304 Stainless Steel Pipe Chemical Composition

Grade		Carbon	Manganese	Silicon	Phosphorous	Sulfur	Chromium	Molybdenum	Nickel	Nitrogen
304	Minimum	-	-	-	-	-	18.0	-	8.0	-
	Maximum	0.08	2.0	0.75	0.045	0.030	20.0		10.5	0.10

 

ASME SA 312 TP304 Welded Tube Mechanical Strength

Grade	Hardness	Yield Strength	Elongation	Tensile Strength
304	92	205	40	515

 

Physical Properties of SS 304 Tube

Grade	Density	Elasticity	Mean Coeff. of Thermal Expansion			Thermal conduct.		Specific Heat 0 To 1000C	Resistivity
			0 To 1000 C	0 To 3150 C	0 To 5380 C	at 1000 C	at 5000 C
304	8000	193	17.2	17.8	18.4	16.2	21.5	500	720

 

ASTM A312 TP304 Stainless Steel Tube Surface Finish

Surface Finish	Internal Surface		Exterbal Surface
	μ inch	μm	μ inch	μm
Beight Annealed	25, 40, 20, 32	0.6, 1.0, 0.5, 0.8	32	0.8
Electro Polish	10, 7,5, 15,	0.13, 0.20, 0.38, 0.25	32	0.8
Mechanical Polish	25, 40, 32, 20,	0.6, 1.0, 0.8, 0.5	32	0.8
Annealed and Pickled	Null	Null	40 / Null	1 / Null

 

SA 312 TP 304 Welded Tube Weight Chart

NPS (DN)	ID	SCH	OD IN (Milimeter)	WEIGHT LB/FT (KG/M)	WT IN (Milimeter)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	84.085 (126.032)	0.025 (6.035)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	95.028 (141.09)	0.0281 (7.014)
32 (800)	.0.0.0	10	32.00 (813)	105.069 (157.025)	0.0312 (7.092)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	116.041 (173.035)	0.0344 (8.074)
32 (800)	STD	.0.0.0	32.00 (813)	126.078 (188.083)	0.0375 (9.053)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	137.012 (204.009)	0.0406 (10.031)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	147.078 (220.01)	0.0438 (11.013)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	158.008 (235.029)	0.0469 (11.091)
32 (800)	XS	20	32.00 (813)	168.037 (250.065)	0.05 (12.07)
32 (800)	.0.0.0	.0.0.0	32.00 (813)	188.087 (281.009)	0.0562 (14.027)
32 (800)	.0.0.0	30	32.00 (813)	209.062 (312.017)	0.0625 (15.088)

 

ASTM A312 TP304 Pipe Sizes, Dimensions & Tolerances

NPS	*t/D	Tolerance, % from Nominal
1/8"~2.5"	All	+20.0	-12.5
3"~18"	≤5%	+22.5	-12.5
3"~18"	>5%	+15.0	-12.5
≥20" Wld.	All	+17.5	-12.5
≥20" smls	≤5%	+22.5	-12.5
≥20" smls	>5%	+15.0	-12.5

 

Heat Treatment of ASTM A312 TP304 Pipe

ASTM A312 TP304 piping must undergo solution annealing (solution treatment) to maximize corrosion resistance, relieve welding stresses, and dissolve chromium carbides. This process requires heating the piping to a temperature of no less than 1900°F (1040°C), followed by rapid cooling or water quenching.

 

The ASME SA312 TP304 seamless steel pipes we supply are delivered in a heat-treated condition, in strict accordance with specified heat treatment temperatures as well as cooling and inspection requirements. ASTM A312 TP304 ERW steel pipes must undergo mechanical property testing, including transverse or longitudinal tensile tests and flattening tests. In accordance with the EN 10204 standard, we can provide Mill Test Certificates (MTCs) for ASTM A312 TP304 steel pipes that meet the requirements of 3.1 or 3.2.

 

Inspection & Tests
Visual examination, dimensional inspection, PMI chemical analysis, tensile test, flattening test, bend test, eddy-current test, etching test, radiographic examination (for welded pipes), intergranular corrosion test (upon request).

 

Packaging and Delivery

Item	Details
Package	Waterproof paper, edge protection, wooden pallets or crates
Loading Port	Tianjin, Qingdao, Shanghai, or any major Chinese seaport
Container Capacity	1×20ft: Max 25 Tons, Max 5.8m length 1×40ft: Max 25 Tons, Max 11.8m length
Delivery Time	7–15 working days depending on order quantity

FAQ

Q: Is ASTM A312 TP304 a seamless pipe or a welded pipe?
Answer: ASTM A312 covers seamless, straight-seam welded, and heavily cold-worked welded (HCW) stainless steel pipes. When placing an order, it is essential to clearly specify whether "SMLS" (Seamless) or "WLD" (Welded) is required, as there are significant differences in pressure-bearing capacity and price between the two.

Q: What is the difference between TP304 and TP304L? Which one should I choose?
Answer:
TP304: Carbon content ≤ 0.08%. It offers slightly higher strength and is suitable for general corrosive environments.
TP304L: Carbon content ≤ 0.03% (where "L" stands for Low Carbon). It is specifically designed for welding applications to prevent intergranular corrosion within the heat-affected zone (HAZ) of welds. If your project involves extensive welding, it is recommended to choose TP304L.

Q: What is the difference between ASTM A312 and ASTM A213?
Answer:
A312 is primarily used for piping systems (Pipes); it focuses on fluid conveyance and emphasizes pipe diameter and pressure ratings.
A213 is primarily used for boiler, superheater, and heat exchanger tubes (Tubes); it focuses on heat exchange performance and imposes stricter requirements regarding wall thickness tolerances.

Q: What is the maximum service temperature for TP304 stainless steel pipe?
Answer: In oxidizing environments, TP304 can withstand oxidation temperatures of up to 870°C. However, for continuous service within the temperature range of 425°C to 815°C, it is recommended to switch to TP304L or TP321 to avoid corrosion caused by carbide precipitation.