ASTM A312 Stainless Steel Pipe Specification

ASTM A312 / A312M, Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes, covering Austenitic stainless steels, and manufactured both welded and seamless type for option.

ASTM A312 stainless steel pipe is widely used for high temperature service and general service, pipe size from 1/8 inch to 30 inch for outside diameter, wall thickness from Schedule 5S to 80S。

ASME SA312 is ASTM A312 equivalent specification.

ASTM A312 Specification

Chemical Requirements and Mechanical Properties

ASTM A312 covers Austenitic stainless steels, including TP304, TP304L, TP304H, TP304LN, TP309S, TP309J, TP310S, TP310H, TP316, TP316L, TP316H, TP316TI, TP317, TP317L, TP321, TP321H, TP347, TP347H, these grades have unique composition and properties, common stainless steel grades with chemical composition and properties are specified as following.

Chemical Composition

Grade Carbon Silicon Manganese Chromium Nickel Molybdenum Sulfur Phosphorous
TP304 0,08 1,0 2.00 18.0 – 20.0 8.0 – 11.0 0,03 0,045
TP304L 0,035 1,0 2.00 18.0 – 20.0 8.0 – 13.0 0,03 0,045
TP316 0,08 1,0 2.00 16.0 – 18.0 10.0 – 14.0 2.00 – 3.00 0,03 0,045
TP316L 0,035 1,0 2.00 16.0 – 18.0 10.0 – 15.0 2.00 – 3.00 0,03 0,045
TP321 0,08 1,0 2.00 17.0 – 19.0 9.0 – 12.0 0,03 0,045

Mechanical Properties

Grade UNS Tensile Strength
min, ksi [MPa]
Yield Strength
min, ksi [MPa]
TP304 S30400 75 [515] 30 [205]
TP304L S30403 70 [485] 25 [170]
TP304H S30409 75 [515] 30 [205]
TP304N S30451 80 [550] 35 [240]
TP304LN S30453 75 [515] 30 [205]
TP309S S30908 75 [515] 30 [205]
TP310S S31008 75 [515] 30 [205]
TP316 S31600 75 [515] 30 [205]
TP316L S31603 70 [485] 25 [170]
TP316H S31609 75 [515] 30 [205]
TP316N S31651 80 [550] 35 [240]
TP316LN S31653 75 [515] 30 [205]
TP317 S31700 75 [515] 30 [205]
TP317L S31703 75 [515] 30 [205]
ASTM A312 TP304 Seamless Stainless Steel Pipe

We produce ASTM A312 TP304 seamless stainless steel pipe with various sizes, pipe comfrom to ASTM A312 specification, TP304 seamless pipe have good corrosion resiistance。

ASTM A312 TP304L Welded Stainless Steel Pipe

Dongshang Stainless produce welded stainless steel pipe complying with A312 specification, intending for high-temperature and general corrosive service.

ASTM A312 pipe Manufacturing

ASTM A312 Seamless Pipe

Pipe should be made from stainless steel billet in hot rolling or cold drawn, no any welding process during manufacturing, seamless pipe has better pressure to withstand, annealing solution and pickling finishing condition, applied for high temperature and corrosion environment.

ASTM A312 Welded Pipe

No additional metal using automatic welding process for welded pipe, made from stainless steel strip or plate, both single welding and double welding for option, smail diameter and arge diameter are available, annealing pickling finish.

Heavily Cold-worked (HCW) Pipe

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. Prior to cold working, the weld shall be 100 % radiographically inspected.

Welded pipe and HCW pipe of 14 and smaller than NPS 14 shall have a single longitudinal weld. After approval by the purchaser, the welded pipe and HCW pipe with an NPS greater than NPS 14 shall have a single longitudinal weld or shall be manufactured by forming and welding two longitudinal sections of flat stock.

Heat Treatment

All pipe shall be furnished in the heat-treated condition in accordance with the required heat treating temperature and cooling requirements, pipes shall be individually quenched in water or rapidly cooled by other means (direct quenched).

The pipe shall be free of scale and contaminating exogenous iron particles。 Pickling, blasting, or surface finishing is not mandatory when pipe is bright annealed。

ASTM A312 Stainless Steel Pipe Tolerances

Outside Diameter

Outside Diameter, NPS Tolerance, Inch
1/8 to 1-1/2, incl over 1/16 under 1/32
over 1-1/2 to 4, incl over 1/32 under 1/32
over 4 to 8, incl over 1/16 under 1/32
over 8 to 18, incl over 3/32 under 1/32
over 18 to 26, incl over 1/8 under 1/32
over 26 to 34, incl over 5/32 under 1/32
over 34 to 48, incl over 3/16 under 1/32

Wall Thickness

NPS Wall Thickness Tolerance, %
1/8 to 2-1/2 incl., all t/D ratios over 20.2 under 12.5
over 3 to 18 incl., t/D up to 5% incl. over 22.5 under 12.5
over 3 to 18, incl., t/D > 5% over 15.0 under 12.5
20 and large, welded, all t/D ratios over 17.5 under 12.5
20 and large, seamless, t/D up to 5% incl. over 22.5 under 12.5
>20 and large, seamless, t/D > 5% over 15.0 under 12.5

ASTM A312 welded and seamless pipe sizes and chart

ASTM A312 stainless steel pipe sizes and dimensions should conform to ANSI B36.19, nominal pipe size (NPS) ranges from NPS 1/8 [10.29 mm] to NPS 30 [762 mm], Schedule number for wall thickness from Sch 5s to Sch 80s, value stated respective for specific size, average wall and minimum wall pipe are available upon request.

Note over NPS 12 sizes are actual sizes, not like below NPS 12 size values.

Nominal SizeODWall Thickness, SCHEDULE
NPSDNmm5S10S40SSTD80S
1∕8610.31.241.731.732.41
1∕4813.71.652.242.243.02
3∕81017.21.652.312.313.2
1∕21521.31.652.112.772.773.73
3∕42026.71.652.112.872.873.91
12533.41.652.773.383.384.55
1 1∕43242.21.652.773.563.564.85
1 1∕24048.31.652.773.683.685.08
25060.31.652.773.913.915.54
2 1∕265732.113.055.165.167.01
38088.92.113.055.495.497.62
3 1∕290101.62.113.055.745.748.08
4100114.32.113.056.026.028.56
5125141.32.773.46.556.559.53
6150168.32.773.47.117.1110.97
8200219.12.773.768.188.1812.7
10250273.13.44.199.279.2712.7
12300323.93.964.579.539.5312.7
14350355.63.964.789.53
16400406.44.194.789.53
18450457.24.194.789.53
205005084.785.549.53
22550558.84.785.549.53
24600609.65.546.359.53
26650660.49.53
28700711.29.53
307507626.357.929.53

Beveled Stainless Steel Pipe

Beveled end A312 stainless steel industrial pipe is used to joint fitting or other connectors, there are different angles and tolerances for special applications, it is easy to welding, and save installing time, cost effective.

Testing and inspection

  • Mechanical Tests
  • Grain Size Determinations
  • Weld Decay Tests
  • Transverse or Longitudinal Tension Test
  • Hydrostatic or Nondestructive Electric Test
  • Flattening Test (option)
  • Radiographic Examination (option)
  • Intergranular Corrosion Test (option)
  • Weld Decay Test (option)

Reference Documents

  • ASTM A999 / A999M – Standard Specification for General Requirements for Alloy and Stainless Steel Pipe
  • ASTM A1016 / A1016M – Standard Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes
  • ASME B36.10 – Welded and Seamless Wrought Steel Pipe
  • ASME B36.19 – Stainless Steel Pipe
ASTM A312 Stainless Steel Pipe Specification