Comprehensive information on ASTM A312 steel pipes

Comprehensive information on ASTM A312 steel pipes
ASTM A312 is a key standard for austenitic stainless steel tubes (seamless, welded, cold-worked) used in high-temperature/corrosive environments. It covers material grades such as TP304/L and TP316/L, and is suitable for industries such as petrochemical, food, and pharmaceutical. This standard specifies manufacturing processes, testing methods (tensile, flattening), dimensions (NPS 1/8" to 30"+), and requires materials to be clean and free of oxide scale to ensure reliability. It guarantees strength, ductility, and corrosion resistance, thus providing reliable performance even under harsh conditions.
What is ASTM A312 pipe?
ASTM A312 pipe is a general-purpose stainless steel pipe widely used in various industries. Its diameter ranges from 1/8 inch to 30 inches, and its wall thickness ranges from SCH 10S to SCH 80S. Commonly used material grades are TP304/304L and TP316/316L.


Outer Diameter: 10.3mm-609.6mm
Wall Thickness: 0.2mm-60mm
Length: 5-12m or customized upon request
Applications: Low-pressure liquid, water, gas, oil pipes, boiler engineering piping, etc.
Additional Processes: Plain or threaded connection (with socket or bevel, with plastic cap), hydrostatic testing, eddy current testing, infrared thermal analysis
Surface Treatment: Bright annealing, pickling, sandblasting or passivation
Delivery Condition: Hot rolled, cold drawn
Steel Grades: TP304, TP304L, TP316, TP316L, TP321, TP347
ASTM A312 Chemical Composition
| Steel Grade | ASTM A312 Chemical Composition % Max | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Mn | P | S | Si | Cr | Ni | Mo | N B | Nb | Ti | |
| TP304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | … | … | … . | … |
| TP304H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | … | … | … | … |
| TP304L | 0.035 D | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-13.0 | … | … | … | … |
| TP310S | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 24.0-26.0 | 19.0-22.0 | 0.75 | |||
| TP316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 11.0-14.0 | 2.00-3.00 | … | … | … |
| TP316L | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | … | … | … |
| TP316H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 11.0-14.0 | 2.00-3.00 | … | … | … |
| TP316Ti | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | 0.10 | … | 5x(C+N)-0.70 |
| TP321 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-12.0 | … | 0.10 | … | 5C-0.70 |
| TP321H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-12.0 | … | … | … | 4C-0.60 |
| TP347 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-13.0 | 10xC-1.00 | … | ||
| TP347H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-13.0 | … | … | 8xC-1.00 | … |
ASTM A312 Mechanical Property
| ASTM A312 Mechanical Properties | |||||
|---|---|---|---|---|---|
| Steel Grade | Heat Treatment |
Temperure Min. º F(º C) |
Tensile Strength Ksi (MPa), Min. |
Yield Strength Ksi (MPa), Min. |
Elongation %, Min |
| TP304 | Solution | 1900 (1040) | 75(515) | 30(205) | 35 |
| TP304L | Solution | 1900 (1040) | 70(485) | 25(170) | 35 |
| TP304H | Solution | 1900 (1040) | 75(515) | 30(205) | 35 |
| TP310S | Solution | 1900 (1040) | 75(515) | 30(205) | 35 |
| TP316 | Solution | 1900(1040) | 75(515) | 30(205) | 35 |
| TP316L | Solution | 1900(1040) | 70(485) | 25(170) | 35 |
| TP316H | Solution | 1900(1040) | 75(515) | 30(205) | 35 |
| TP316Ti | Solution | 1900(1040) | 75(515) | 30(205) | 35 |
| TP321 | Solution | 1900(1040) | 75(515) | 30(205) | 35 |
| TP321H | Solution | Cold: 2000(1100) Hot: 1925(1050) |
75(515) | 30(205) | 35 |
| TP347 | Solution | 1900(1040) | 75(515) | 30(205) | 35 |
| TP347H | Solution | Cold: 2000(1100) Hot: 1925(1050) |
75(515) | 30(205) | |
ASTM A312 Equivalent steel grade
| ASTM A312 | JIS G3459 | DIN 17440 | BS | NF |
|---|---|---|---|---|
| TP304 | SUS 304 TP | X5CrNi 18 9 | 304S18 | A 49-230 |
| TP304H | SUS 304 HTP | 304S59 | A 49-214 | |
| TP310 | 304 LTP | X2 CrNi 19 9 | 304S14 | A 49-230 |
| TP316 | SUS 304L TP | |||
| TP316H | 310STP | X5 CrNiMo 18 10 | 316S18 | A 35-573 |
| TP316L | SUS 316 TP | 316S59 | A 49-230 | |
| TP321 | SUS 316 LTP | X2 CrNiMo 18 10 | 316S14 | A 49-230 |
| TP347 | 316 HTP | x10 CrNiTi 18 9 | 321S18 | A 49-230 |
| TP347H | SUS 316 LTP | X5 CrNiNb 18 9 | 347S18 | A 35-573 |
The nominal wall thickness of ASTM A312 (seamless and straight seam welded steel pipe)
| NPS | ASTM A312 WT Tolerance, % | |
|---|---|---|
| + | – | |
| 1/8-2 1 /2 | 20.0 | 12.5 |
| 3~18, t/D≤ 5% | 22.5 | 12.5 |
| 3~18, t/D> 5% | 15.0 | 12.5 |
| ≥ 20, welded | 17.5 | 12.5 |
| ≥ 20, seamless, t/D≤ 5% | 22.5 | 12.5 |
| ≥ 20, seamless, t/D> 5% | 15.0 | 12.5 |
ASTM A312 Stainless Steel Pipes OD Tolerance
| NPS | ASTM A312 OD Tolerance | |||
|---|---|---|---|---|
| + | – | |||
| inch | mm | inch | mm | |
| 1/8~1 1 /2 > 1 1 /2~4 > 4~8 > 8~18 > 18~26 > 26~34 > 34~48 |
1/64(0.015) 1/32(0.031) 1/16(0.062) 3/32(0.093) 1/8(0.125) 5/32(0.156) 3/16(0.187) |
0.4 0.8 1.6 2.4 3.2 4.0 4.8 |
1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) |
0.8 0.8 0.8 0.8 0.8 0.8 0.8 |



