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Chrome-molyForged flanges & fittingsTG-MG-114 · Rev. 1 · October 2026

ASTM A182 F9 — Chemical Composition & Mechanical Properties

ASTM A182 F9 is a chrome-moly alloy steel grade for forged flanges & fittings (UNS K90941, EN / W.Nr 1.7386). It is also known as 9Cr-1Mo. This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group manufactures flanges and fittings in this grade.

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ASTM A182 F9 at a glance

SpecificationASTM A182 F9
Material familyChrome-moly alloy steel
Product formForged flanges & fittings
UNS numberK90941
EN / W.Nr equivalent1.7386
Also known as9Cr-1Mo
DocumentTG-MG-114 · Rev. 1 · October 2026

Typical service

Refinery furnace and high-temperature sulphidic service

Heat treatment

Annealed, or normalised and tempered 675 °C min

Chemical composition of ASTM A182 F9 (weight %)

C0.15 max
Mn0.30–0.60
P0.030 max
S0.030 max
Si0.50–1.00
Cr8.0–10.0
Mo0.90–1.10

Single values are maximums unless shown as a range or “min”.

Mechanical properties

Tensile strength, min585 MPa
Yield strength (0.2 % offset), min380 MPa
Elongation, min20 %
Hardness179–217 HBW

About chrome-moly alloy steel

Chrome-moly steels are low-alloy steels with 1–9 % chromium and 0.5–1 % molybdenum. Chromium gives oxidation and sulphidation resistance; molybdenum gives creep strength at high temperature. They are the standard choice for steam and hot hydrocarbon service above the carbon-steel range.

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 A182 F9

All equivalents
Standard systemNearest equivalent grade
USA — ASTM / ASMEASTM A182 F9 · ASME SA-182 F9
USA — UNSK90941
Europe — EN designationX11CrMo9-1 (EN 10216-2)
Europe — W.Nr1.7386
Japan — JISSTPA26 / SFVAF9
China — GB / NB12Cr9MoI (GB/T 9948) / 1Cr9Mo1
China — old GB designation1Cr9Mo1
UK — BS (withdrawn)BS 3604 629

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 formSpecification / grade
Wrought butt-weld fittingsASTM A234 WP9 Cl.1
Seamless pipeASTM A335 P9

FAQ

ASTM A182 F9: common questions

What is the minimum yield strength of ASTM A182 F9?

380 MPa, with a minimum tensile strength of 585 MPa.

What is the carbon content of ASTM A182 F9?

0.15 max %.

What is the UNS number and EN equivalent of ASTM A182 F9?

UNS K90941; the nearest European designation is W.Nr 1.7386. Equivalents are close but not identical — check the specification if substituting.

How is ASTM A182 F9 heat treated?

Annealed, or normalised and tempered 675 °C min.

What is the Chinese (GB) equivalent of ASTM A182 F9?

The nearest Chinese equivalent is 12Cr9MoI (GB/T 9948) / 1Cr9Mo1, formerly 1Cr9Mo1. Equivalents are close but not identical — compare chemistry and properties before substituting.

What is the JIS equivalent of ASTM A182 F9?

The nearest Japanese (JIS) equivalent is STPA26 / SFVAF9.

Does Teshi Group supply ASTM A182 F9?

Teshi Group manufactures flanges and fittings in this grade. Send your size, rating and quantity to info@teshigroup.com for a quotation with EN 10204 3.1 certificates.

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