Specifications

Outside diameters and wall thicknesses by size and schedule are listed in our pipe schedule chart.

Which grade for which service?

• ASTM A106 Grade B – the default for process piping at ambient and elevated temperatures, steam and hydrocarbon lines.
• ASTM A53 Grade B (Type S) – general pressure and mechanical use, water, air and gas lines; often dual certified with A106 Gr B.
• API 5L – line pipe for oil and gas gathering and transmission; PSL2 for critical and sour service.
• ASTM A333 Grade 6 – impact-tested pipe for low-temperature lines.
• ASTM A106 Grade C – higher strength for selected high-pressure duties.

Many mills certify a single pipe to A106 Gr B, A53 Gr B and API 5L Gr B together, which simplifies stocking and lets one pipe meet several specifications.

Chemical composition and mechanical properties

The ASTM A106 requirements are shown below; the mill test certificate gives the actual values for each heat.

Limits on combined Cr, Cu, Mo, Ni and V, and the manganese allowance for lower carbon, are as given in the standard.

Elongation requirements depend on specimen type and wall thickness, as given in the standard.

Testing and IBR certification

Seamless carbon steel pipe is tested as its standard requires – typically chemical analysis, tensile, bend or flattening tests and a hydrostatic or non-destructive electric test on each length. A333 pipe is also impact tested at the specified temperature, and API 5L PSL2 pipe has mandatory toughness testing and tighter chemistry. For boilers and steam lines in India covered by the Indian Boiler Regulations, pipes are supplied with IBR certification when the order calls for it; please mention IBR in your enquiry so the mill documents and inspection are arranged accordingly.

For pipelines, API 5L pipe can also be supplied with internal coatings and with ends prepared for field welding.

Coating, marking and packing

Pipes are supplied black (mill finish), with a temporary varnish or paint, galvanised, or with external coatings such as 3LPE or FBE for buried pipelines, as specified. Each length is marked with the standard, grade, size, schedule, heat number and the mill's identification. Bevelled ends are protected with caps, and pipes are bundled with steel straps or shipped loose depending on size.

Ordering

Please give the standard and grade, size and schedule, length, end finish, coating, quantity, and any IBR, impact test, NACE MR0175 / ISO 15156 or third-party inspection requirement.

Applications and related products

Carbon steel seamless pipes are used for process and hydrocarbon lines, steam and condensate, boiler feed water, compressed air, firewater, oil and gas flowlines and pipelines, and structural and mechanical uses. They are matched with carbon steel pipe fittings such as A234 WPB, carbon steel flanges such as A105, and fasteners. For larger or lower-pressure lines, carbon steel ERW pipes are an alternative. We also supply carbon steel plates and round bars. Material guidance is on the carbon steel page, and other seamless materials on the seamless pipes and tubes page.