Alloy Grade UNS: 440C – Martensitic Stainless Steel

  • Overview

    This martensitic stainless steel is one of the hardest stainless grades when fully hardened and stress relieved. This hardness, coupled with permanent carbides in the structure, makes this high carbon alloy exceptionally resistant to abrasive wear. Chromium content provides good corrosion resistance. Before welding, it should be preheated and stress-relieved immediately after welding. It is machinable in the annealed condition and is magnetic. This 440C alloy has higher levels of carbon compared to 440A and 440B.

  • Typical Uses

    Valve components, pump parts, shaft sleeves, and bearings.

  • MetalTek Grade

    MTEK 440C

Similar Specifications

Cast UNS: J91639

Wrought UNS: S44004

Wrought Grade: 440C

Cast Grade: 440C

Military/AMS: AMS 5352

* AMS specifying investment casting.

Typical Chemical Composition (% by wt.)

Aluminum: n/a

Carbon: 0.95-1.20

Chromium: 16-18

Manganese: 1

Iron: BAL

Copper: n/a

Nickel: 0.75 MAX

Lead: n/a

Tin: n/a

Silicon: 1

Zinc: n/a

Other: Mo 0.25-0.75

Minimum Mechanical Properties

Brinell Typical:


Heat Treatment: Anneal

NOTES: Brinell value is MAX.