aterials such as TP304, TP304L and TP316 series stainless steels.
ASTM A182 includes corresponding forged stainless-steel component grades used for flanges, fittings and valves.
Common piping combinations therefore include:
| Pipe | Forged Components |
|---|---|
| ASTM A312 TP304/304L | ASTM A182 F304/F304L |
| ASTM A312 TP316/316L | ASTM A182 F316/F316L |
Again, the chemistry may be designed to support compatible service, but the specifications govern different products.
Why Does This Matter When Requesting a Quotation?
Consider an RFQ that says only:
“ASTM A105 seamless pipe, 12 inch.”
That wording immediately creates a technical question.
Does the buyer actually require ASTM A106 pipe?
Is the requirement for a forged and machined hollow?
Is A105 referring to a connected flange or fitting rather than the pipe itself?
Or does the project specification contain a special forged component requirement?
A professional supplier should clarify this before quotation instead of silently assuming the intended material.
The same problem occurs when an RFQ simply asks for “A182 F316 seamless pipe.”
If the requirement is conventional stainless steel pipe, ASTM A312 TP316/TP316L may be the intended product specification.
If the item is a forged flange, fitting or valve component, ASTM A182 F316/F316L may be correct.
Product form matters.
Material Grade Is Only One Part of the Specification
Steel procurement becomes risky when the buyer focuses only on grade.
A complete piping requirement may need to identify:
product form, material specification, grade, dimensional standard, NPS or OD, schedule or wall thickness, manufacturing process, heat treatment, supplementary requirements, NDE, impact testing, hardness limits, hydrostatic testing, end preparation and certification.
For sour service, low-temperature service, offshore projects or owner-specific requirements, additional specifications may apply.
A quotation cannot be technically complete if the inquiry itself does not define the product correctly.
How Procurement Teams Should Write the RFQ
Instead of:
“A106/A105 carbon steel pipe.”
Write:
“Seamless carbon steel pipe, ASTM A106 Gr. B, NPS 8, SCH 80, ASME B36.10M, 6 m random length, quantity XX.”
Then identify the associated components separately:
“Forged carbon steel flange, ASTM A105/A105M, ASME B16.5, NPS 8, Class 600, RF.”
This eliminates ambiguity.
It also allows the supplier to check availability, manufacturing capability and certification more accurately.
A Simple Rule to Remember
ASTM specifications should be read together with the product form they cover.
ASTM A106 → seamless carbon steel pipe.
ASTM A335 → seamless ferritic alloy-steel pipe.
ASTM A312 → austenitic stainless steel pipe.
ASTM A105 → forged carbon steel piping components.
ASTM A182 → forged or rolled alloy and stainless steel piping components.
That distinction is more useful than memorizing a table of supposed “equivalent grades.”
Final Thoughts
In industrial piping, material compatibility is important, but compatibility does not mean that two ASTM standards are interchangeable.
A106 Gr. B pipe may be used in the same piping system as A105 forged components. A335 P22 pipe may be paired with A182 F22 forged components. A312 TP316L pipe may be used together with A182 F316L components.
Each product still has to comply with its own specification.
This is particularly important when sourcing project materials internationally, where a small error in an RFQ can result in incorrect quotations, certification problems and unnecessary delays.
Aspera Steel supports the sourcing of carbon steel, alloy steel, stainless steel and special piping products according to ASTM, ASME, API and project-specific requirements.
If you are unsure whether the material designation in your RFQ matches the required product form, send us the specification, grade, size, quantity and service conditions. Our technical team can review the requirement before quotation.