ASTM A182 F11 Cl.1 — Chemical Composition & Mechanical Properties
ASTM A182 F11 Cl.1 is a chrome-moly alloy steel grade for forged flanges & fittings (UNS K11597, EN / W.Nr ≈ 1.7335 (13CrMo4-5)). It is also known as 1¼Cr-½Mo. This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group manufactures flanges and fittings in this grade.
ASTM A182 F11 Cl.1 at a glance
| Specification | ASTM A182 F11 Cl.1 |
|---|---|
| Material family | Chrome-moly alloy steel |
| Product form | Forged flanges & fittings |
| UNS number | K11597 |
| EN / W.Nr equivalent | ≈ 1.7335 (13CrMo4-5) |
| Also known as | 1¼Cr-½Mo |
| Document | TG-MG-131 · Rev. 1 · October 2026 |
Typical service
Lower-strength 1¼Cr-½Mo forgings for steam and refinery piping
Heat treatment
Annealed, normalised and tempered, or quenched and tempered
Chemical composition of ASTM A182 F11 Cl.1 (weight %)
Single values are maximums unless shown as a range or “min”.
Mechanical properties
| Tensile strength, min | 415 MPa |
|---|---|
| Yield strength (0.2 % offset), min | 205 MPa |
| Elongation, min | 20 % |
| Hardness | 121–174 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 F11 Cl.1
All equivalents| Standard system | Nearest equivalent grade |
|---|---|
| USA — ASTM / ASME | ASTM A182 F11 Cl.1 · ASME SA-182 F11 Cl.1 |
| USA — UNS | K11597 |
| Europe — EN designation | 13CrMo4-5 |
| Europe — W.Nr | 1.7335 |
| Japan — JIS | STPA23 / SFVAF11A |
| China — GB / NB | 15CrMoG (GB/T 5310) / 14Cr1MoR (GB/T 713.2) |
| China — old GB designation | 15CrMo |
| UK — BS (withdrawn) | BS 3604 621 |
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 WP11 Cl.1 |
| Seamless pipe | ASTM A335 P11 |
Standards for ASTM A182 F11 Cl.1
All material standardsFAQ
ASTM A182 F11 Cl.1: common questions
What is the minimum yield strength of ASTM A182 F11 Cl.1?
205 MPa, with a minimum tensile strength of 415 MPa.
What is the carbon content of ASTM A182 F11 Cl.1?
0.05–0.15 %.
What is the UNS number and EN equivalent of ASTM A182 F11 Cl.1?
UNS K11597; the nearest European designation is W.Nr ≈ 1.7335 (13CrMo4-5). Equivalents are close but not identical — check the specification if substituting.
How is ASTM A182 F11 Cl.1 heat treated?
Annealed, normalised and tempered, or quenched and tempered.
What is the Chinese (GB) equivalent of ASTM A182 F11 Cl.1?
The nearest Chinese equivalent is 15CrMoG (GB/T 5310) / 14Cr1MoR (GB/T 713.2), formerly 15CrMo. Equivalents are close but not identical — compare chemistry and properties before substituting.
What is the JIS equivalent of ASTM A182 F11 Cl.1?
The nearest Japanese (JIS) equivalent is STPA23 / SFVAF11A.
Does Teshi Group supply ASTM A182 F11 Cl.1?
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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