ASTM A106

USED FOR:

This standard governs seamless carbon steel pipe intended for high-temperature service.

It applies specifically to seamless (not welded) pipe used in process piping systems where elevated operating temperatures are a design consideration — typical examples include steam lines, hot process fluid lines, and refinery/petrochemical piping.

RELATED STANDARDS:

• Sibling specs: ASTM A53 covers seamless and welded carbon steel pipe for general-purpose and structural applications, without the high-temperature service qualification built into A106; ASTM A333 covers seamless and welded carbon/alloy steel pipe intended for low-temperature service, essentially occupying the opposite end of the temperature spectrum from A106.
• Design code that invokes it: ASME B31.3 (Process Piping) and ASME B31.1 (Power Piping) both reference A106 as an approved material specification for pressure design calculations, allowable stress determination, and temperature derating.
• Dimensional standard that pairs with it: ASME B36.10M defines the outside diameter, wall thickness, and schedule designations that apply to A106 pipe; the material specification itself defines chemistry and mechanical properties, not geometry.

GRADE / TYPE RANGE:
A106 covers three grades — A, B, and C — differentiated primarily by carbon content and minimum tensile/yield strength, with strength increasing from Grade A through Grade C. Grade B is by a wide margin the most commonly specified in industrial and oil & gas applications, generally viewed as the best balance between mechanical strength, weldability, and cost. Grade C offers higher strength but at the expense of somewhat reduced weldability, so it tends to appear in more specific high-stress applications rather than as a default choice.

DESCRIPTION:
ASTM A106 covers seamless carbon steel pipe manufactured by hot finishing or cold drawing, produced without a longitudinal weld seam — a key distinction from A53, which permits both seamless and welded (ERW) product. The standard sets requirements for chemical composition, tensile properties, hydrostatic or nondestructive testing, and dimensional tolerances, and it specifies pipe marking requirements for material traceability. The absence of a weld seam is what makes A106 well-suited to elevated-temperature and cyclic service, where a weld line could otherwise represent a metallurgical weak point.

TYPICAL INDUSTRY USE:
We most commonly see A106 specified in refinery and petrochemical process piping, power generation steam systems, and other high-temperature industrial piping applications where seamless construction is a project requirement.

IMPORTANT NOTES:

• A106 is frequently confused with A53 Grade B — dimensionally and even chemically the two can look similar, but A106 is qualified specifically for high-temperature service and does not include a welded product option, while A53 does. Specifying the wrong one is a common procurement error, particularly when copying legacy specs across projects.
• A106 includes optional supplementary requirements (such as S1 through S6 in various editions) covering additional testing like impact testing or more stringent NDE — these are not automatically included and must be explicitly called out in the purchase specification if required.
• We recommend checking sour service applicability against NACE MR0175/ISO 15156 separately, since standard A106 grades are not inherently qualified for sour service without additional controls or supplementary requirements agreed upon between purchaser and manufacturer.
• We generally advise confirming with the client/project spec which grade is required before ordering, since Grade B is the default assumption in most piping specs but this should never be assumed silently on a job with non-standard service conditions.