431 Stainless Steel

Shapes Available

  • Round Bar
  • Wire


  • Aerospace
  • Marine
  • Oil Refining

Industry Names

  • UNS S43100


  • Stainless Steel


  • AMS 5628
  • ASTM A276 (Bar)
  • ASTM A479 (Bar)
  • MIL-S-18732
  • UNS S43100


  • Bolts
  • Fasteners
  • Marine Fixtures
  • Pump Shafts


  • Corrosion Resistant in a Variety of Marine and Chemical Environments
  • Excellent Corrosion Resistance

431 Stainless Steel has been designed to improved corrosion resistance and toughness properties than other 400 stainless grades especially in a quench-hardenable stainless. 431 would work well in marine environments as well as in aerospace applications such as aircraft fasteners and fittings. 431 has great impact strength at a high hardness level.

Out of all the martensitic grades of stainless steel 431 has the best corrosion resistance. Some other applications for 431 include: bomb racks, bolts, pump shafts, valve stems and aircraft fasteners. Only the age hardenable martensitic stainless grades could achieve greater resistance to corrosion. 431 is available in round bar, strip and wire.

Looking for where to buy 431 stainless steel or 431 round bar? Call Michlin Metals today!

Please contact us to request a quote. We specialize in hard to find material.

We work closely with many manufacturers in the aerospace & defense industry. We work with NADCAP approved heat treaters and testing laboratories. We can supply DFARS compliant material.

Metal Properties
Electrical Resistivity 70° Ohms (circ mil./ft.)
Modulus of Elasticity 29.0 X 10^3
Density 0.2800 lb/inch³
Chemical Composition
C- 0.20
Cr15.00 17.00
Fe- Balance
Mn- 1.00
Ni1.25 2.50
P- 0.040
S- 0.030
Si- 1.00
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