What are Line Material A106 and its Grades

Hi Macsimus,

ASTM A106 Standard Specification for seamless carbon steel pipe for high temperature service.

It is a low carbon steel with good ductility widely used in the oil and gas industry for both pipelines and facility installation. It is not Charpy impact tested, and so should not be used in applications where the temperature is likely to fall substantially below 0^oC. It is a workhorse grade of steel pipe, that is easy to work with and quite forgiving.

It comes in three grades A, B & C, the differences being in the minimum tensile and yield strength, and maximum allowable carbon content, As follows

Grade A: Yield Strength 30,000 PSI, Tensile Strength 48,000 PSI, max Carbon 0.25 wt %

Grade B: Yield Strength 35,000 PSI, Tensile Strength 60,000 PSI, max Carbon 0.30 wt %

Grade C: Yield Strength 40,000 PSI, Tensile Strength 70,000 PSI, max Carbon 0.35 weight %

Further to what has been said, I would like to add that, its classification / gradations has been listed in ASME Sec. IX code, under QW - 422 Ferrous P numbers and it will help you to decide on WPS - PQR Qualifications.

SA 106 Gr. A falls under P1- Gr. 1.

SA 106 Gr. B falls under P1- Gr. 1.

SA 106 Gr. C falls under P1- Gr. 2.

This will help you to decide on the welding consumables to be used while welding the said grades.

"It is not Charpy impact tested, and so should not be used in applications where the temperature is likely to fall substantially below 0^oC"

I don't agree with you for that statement, since we used to use this pipe material at services with a lower temp. reaches -29^oC without impact test.

This comply with ASME code Section VIII, Div. 1, Fig. UCS-66, where the pipe material SA106 belong to Curve B, and you can easily notice that the pipe wall thickness up to 0.394" (10 mm) have a MDMT of -20^oF (-28.9 ^oC) and the material at this thickness -and below- is exempted from impact test at the specified MDMT.

For lower temperatures we have to proceed an impact test, otherwise we can select other alloy or stainless steel pipe material.

Hi Abdel,

Thanks for the information.

As the company I work for is a pipe and fitting distributor, not a fabricator, we don't have a copy of ASME boiler and pressure vessel code, just the ASTM standards book.

I am happy you were able to clarify the information I gave!

I love this forum, where we can all work co-operatively to solve problems.

If only it was like this at work!

Hi Zaphod

I can provide you with some ASME articles clarifying that statement. Please send me your e-mail.

You are welcome.

Can anyone explain what dual rated is? i.e. A106 gr.b/c? it meets both b and c requirements but how?

as from IRON-IRON CARBIDE DIAGRAM the ratio of % by wt.& the percentage of carbon steel in steel, depends upon cementite&austenite value