Stainless Steel / 431 ANN

431 Annealed stainless steel is a martensitic stainless steel that is AOD melted. This alloy has excellent corrosion resistance for a 400 series stainless and can be heat treated to high strength levels. This material is typically used for parts and fittings requiring corrosion resistance and high strength at room and elevated [up to 500 F (260 C)] temperature. Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking. This grade is often used in the aerospace industry as fittings and boltings requiring high yield strength.

Chemical Makeup

Element Min Max
Carbon, C 0.12 0.17
Manganese, Mn 0.3 0.8
Silicon, Si 0.2 0.6
Sulfur, S - 0.03
Phosphorus, P 0.04
Chromium, Cr 15.5 16.5
Nickel, Ni 2 3
Molybdenum, Mo - 0.25
Copper, Cu - 0.5
Nitrogen, N - 0.1

Common Applications

  • Aerospace Aerospace
  • Industrial Industrial


  • Heat Treated To High Strength
  • Good Corrosion Resistance

We stock 431 ANN to the following specifications:

  • AMS-2303
  • AMS-5628
  • AMS-S-18732
  • ASTM-A-276
  • ASTM-A-484
  • DMS-1565 EXC. SONIC
  • MIL-S-18732

Click on a cross-section to see the sizes we stock:

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