Seamless

  • Please change the NPS, Grade and other options below to filter the Product Dimension Chart below, and confirm the Wall Thickness with the Schedule.
  • Standard pipe lengths are about 20 foot long. Please indicate in the “More details about the item” box if you need a specific length.
  • Pipes are identified by nominal pipe size (NPS). For sizes 1/8” through 12”, the actual outside diameter is larger than the corresponding NPS while the outside diameter for sizes 14” and up are the same as the NPS. Please consult the pipe chart for dimensional information.
  • To obtain the working pressure, take the required information from the Product Dimensions Chart table and use Barlow’s Formula at the bottom of this page, then divide the result by 4.
  • Seamless (SML) pipe shall be made by a process that does not involve welding at any stage of production.
  • Measurements are given in inches, unless stated otherwise.
  • Pipes made of the following alloys can also be provided on request: 304H, 310, 316H, 317/L, 321, 347H, 904/L, Alloy 20/200/400/600/625/825, Hastelloy, Aluminum 6061-T6, CHROME P5/P9/P11/P22/P91, Titanium
  • Click here to see the full pipe measurement chart.

Additional Information

The information presented above are typical or average values and are not a guarantee of maximum or minimum values

A/SA 312 Permissible variations in outside diameter

Nom. pipe size ins. TOLERANCE
PLUS MINUS
1/8 to 1-1/2, incl. 1/64 (0.015) 1/32 (0.031)
Over 1-1/2 to 4, incl. 1/32 (0.031) 1/32 (0.031)
Over 4 to 8, incl. 1/16 (0.062) 1/32 (0.031)
Over 8 to 18, incl. 3/32 (0.093) 1/32 (0.031)
Over 18 to 24, incl. 1/8 (0.125) 1/32 (0.031)
Seamless and Welded Austenitic Stainless Steel Pipe have a minimum wall thickness that at any point shall not be more than 12.5 per cent under the nominal wall thickness specified.

See ASTM A999 for additional information.

Barlow’s Formula for Theoretical Bursting Pressure

P = 2 (S * T) / O.D.
P – Bursting Pressure (P.S.I.) T – Wall Thickness (Inches)
O.D. – Outside Diameter (Inches) S – Tensile Strength

Typical Tensile Strengths (S)

Stainless Steel (300 Series) S = 70000 to 75000 psi
Chrome Moly (P1 to P5) S = 55000 psi
Chrome Moly (Balance) S = 60000 psi
Alloy 20 S = 80000 psi
904L S = 70000 psi
Duplex s = 90000 psi
Back to top