ASTM A106 Gr.B — Chemical Composition & Mechanical Properties
ASTM A106 Gr.B is a carbon steel grade for seamless pipe (UNS K03006, EN / W.Nr ≈ P235GH). It is also known as A106 B. This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group supplies this grade as a stockist and supplier, and manufactures matching flanges and fittings.
ASTM A106 Gr.B at a glance
| Specification | ASTM A106 Gr.B |
|---|---|
| Material family | Carbon steel |
| Product form | Seamless pipe |
| UNS number | K03006 |
| EN / W.Nr equivalent | ≈ P235GH |
| Also known as | A106 B |
| Document | TG-MG-020 · Rev. 1 · October 2026 |
Typical service
High-temperature carbon-steel process & steam piping
Heat treatment
Hot-finished: none required; cold-drawn: heat treat at 650 °C min
Chemical composition of ASTM A106 Gr.B (weight %)
Other elements and limits: V 0.08 max; Cr+Cu+Mo+Ni+V 1.00 max
Single values are maximums unless shown as a range or “min”.
Mechanical properties
| Tensile strength, min | 415 MPa |
|---|---|
| Yield strength, min | 240 MPa |
| Elongation, min | 30 % |
| Hardness | Not specified |
About carbon steel
Carbon steel is iron with up to about 0.35 % carbon and 1–1.6 % manganese, and no deliberate chromium, nickel or molybdenum. It is the default material for piping in water, steam, oil, gas and general process service from about −29 °C up to roughly 425 °C.
Reference information compiled from the published standard for convenience. It does not replace the current edition of the governing standard, which takes precedence. Verify critical dimensions and properties before design, purchase or fabrication. Teshi Engineers & Sales Promoters (P) Ltd accepts no liability for errors or omissions.
International equivalents of ASTM A106 Gr.B
All equivalents| Standard system | Nearest equivalent grade |
|---|---|
| USA — ASTM / ASME | ASTM A106 Gr.B · ASME SA-106 Gr.B |
| USA — UNS | K03006 |
| Europe — EN designation | P235GH (EN 10216-2) |
| Europe — W.Nr | 1.0345 |
| Japan — JIS | STPG370 (JIS G3454) / STPT370 (JIS G3456) |
| China — GB / NB | 20 (GB/T 8163, GB/T 5310 20G) |
| China — old GB designation | 20 |
| India — IS | IS 1978 / IS 3589 |
| UK — BS (withdrawn) | BS 3602 HFS 360 |
Equivalents are the nearest commonly cited grades. Chemistry, mechanical properties and testing differ between standards — compare them before substituting one for another.
Same alloy in other product forms
| Product form | Specification / grade |
|---|---|
| Wrought butt-weld fittings | ASTM A234 WPB |
| Wrought butt-weld fittings | ASTM A420 WPL6 |
| Seamless & welded pipe | ASTM A333 Grade 6 |
Other carbon steel grades
Carbon steel overviewStandards for ASTM A106 Gr.B
All material standardsFAQ
ASTM A106 Gr.B: common questions
What is the minimum yield strength of ASTM A106 Gr.B?
240 MPa, with a minimum tensile strength of 415 MPa.
What is the carbon content of ASTM A106 Gr.B?
0.30 max %.
What is the UNS number and EN equivalent of ASTM A106 Gr.B?
UNS K03006; the nearest European designation is W.Nr ≈ P235GH. Equivalents are close but not identical — check the specification if substituting.
How is ASTM A106 Gr.B heat treated?
Hot-finished: none required; cold-drawn: heat treat at 650 °C min.
What is the Chinese (GB) equivalent of ASTM A106 Gr.B?
The nearest Chinese equivalent is 20 (GB/T 8163, GB/T 5310 20G), formerly 20. Equivalents are close but not identical — compare chemistry and properties before substituting.
What is the JIS equivalent of ASTM A106 Gr.B?
The nearest Japanese (JIS) equivalent is STPG370 (JIS G3454) / STPT370 (JIS G3456).
Does Teshi Group supply ASTM A106 Gr.B?
Teshi Group supplies this grade as a stockist and supplier, and manufactures matching flanges and fittings. Send your size, rating and quantity to info@teshigroup.com for a quotation with EN 10204 3.1 certificates.
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