Valve Materials
Alloy Family

Chrome-Moly / Alloy Steel Valve Materials

Chrome-molybdenum (alloy) steels are designed for high-temperature and high-pressure service such as power-plant steam and refinery hydroprocessing. Added chromium and molybdenum give creep strength and oxidation resistance well above the limits of plain carbon steel.

When do you use chrome-moly / alloy steel valve materials?

Chrome-molybdenum (alloy) steels are designed for high-temperature and high-pressure service such as power-plant steam and refinery hydroprocessing. Added chromium and molybdenum give creep strength and oxidation resistance well above the limits of plain carbon steel. This family includes 8 grades in our material library, listed below with their service-temperature limits and common designations.

Grade (ASTM)Common NameFormMin °CMax °C
ASTM A182 F91P91 Chrome-Moly (9Cr-1Mo-V)forged-18+650
ASTM A217 C12AGrade 91 Cast Steel (C12A)cast-29+650
ASTM A217 Grade WC61¼Cr½Mo Alloy Steel WC6cast-29+595
ASTM A217 WC9Chrome-Moly WC9 (2.25Cr-1Mo)cast-18+593
ASTM A182 F22 (2¼Cr-1Mo)F22 Chrome-Moly Alloy Steelforged-29+593
ASTM A182 F55Cr-0.5Mo Alloy Steel (Grade F5)forged-29+593
ASTM A182 F111.25Cr-0.5Mo Alloy Steel (F11)forged-29+540
ASTM A217 WC11 (1¼Cr-½Mo)WC11 Chrome-Moly Alloy Steelcast-29+538
Temperature Envelope →See every grade plotted by service temperatureEquivalence Matrix →ASTM / EN / DIN / UNS / JIS cross-reference

Other alloy families

Reviewed by Materials Engineering, Vajra Industrial SolutionsDiscipline: Valve Metallurgy & Materials SelectionLast reviewed: 20 June 2026

Connected Engineering

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Tell us the grade and service — we supply chrome-moly / alloy steel valve bodies and trim with EN 10204 3.1 material certification.

Browse all grades in the valve material library.