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:

0

Heat Treatment: Anneal

NOTES: Brinell value is MAX.

Explore Other Alloys

Gears

Non-Ferrous

Non-ferrous alloys are, literally, materials that are not iron-based. While others may provide non-ferrous materials of other materials, the MetalTek family of non-ferrous alloys are copper-based. In general, these materials deliver high strength, and excellent wear and corrosion resistance. They are often found in marine applications and also bushing, bearing, and gear environments.
Stainless Steel Parts

Stainless Steel

Stainless steels owe their ability to resist corrosion primarily to the presence of a passive film on their surface. Chromium is chiefly responsible for formation of the passive film. Iron ceases to rust at approximately 12% chromium content and resistance to oxidizing corrosives increases rapidly with chromium content up to approximately 20%.
Petrochemical Fittings

Specialty Alloys

Specialty Alloys comprise a broad group of materials that deliver properties for more demanding applications, use more exotic or expensive materials, or require special processes to manufacture. Where standard materials may not offer desired performance, specialty alloys (including those that are modified further) may be a sensible selection.