At a Glance
Finish
Hot-finished / Cold-drawn
Scope
ASTM A106 covers seamless carbon steel pipe intended for high-temperature service. Pipe produced to this specification is suitable for bending, flanging, and similar forming operations. It is available in three grades — A, B, and C — with Grade B being the most widely specified in the industry.
Pipe is furnished in NPS ⅛ through NPS 48 across all standard wall thicknesses per ASME B36.10M. A106 is inherently a seamless product — there is no welded equivalent under this specification.
Grades
Grade A
Nearly obsolete. Rarely specified in modern projects. Grade B meets or exceeds all Grade A requirements.
SMYS / SMTS
30 ksi / 207 MPa
48 ksi / 331 MPa
Grade B
Industry standard. The default specification for the vast majority of piping systems worldwide.
SMYS / SMTS
35 ksi / 241 MPa
60 ksi / 414 MPa
Grade C
Highest strength grade within A106. Uncommon in standard piping — the added strength is rarely the limiting design factor at the temperatures where carbon steel is appropriate.
SMYS / SMTS
40 ksi / 276 MPa
70 ksi / 483 MPa
Heat Treatment
Heat treatment is not a requirement under ASTM A106 for any grade. When specified, it is done at the discretion of the purchaser via the purchase order. Normalizing is the most common treatment when invoked. Stress-relieving and full annealing are less common but permissible.
Finish: A106 pipe is predominantly furnished hot-finished. Cold-drawn (cold-finished) is technically permissible but rare in practice and typically only seen in smaller diameters or specialty applications.
Key Requirements
Hydrostatic Test: Each length of pipe must be tested to a calculated hydrostatic pressure, or alternatively subjected to NDE per supplementary requirements.
Residual Element Limit: The sum of Cr + Cu + Mo + Ni + V shall not exceed 1.00% on heat analysis.
Marking: Each pipe length is marked with the ASTM designation, grade, size, wall thickness or schedule, heat number, length, and manufacturer's mark.