440C is a martensitic stainless steel alloy and 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. The 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.
Valve components, pump parts, shaft sleeves, and bearings.
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.)
Nickel: 0.75 MAX
Other: Mo 0.25-0.75
Minimum Mechanical Properties
Heat Treatment: Anneal
NOTES: Brinell value is MAX.
Explore Other Alloys
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 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%.
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.