431 Stainless Steel

Type 431 stainless steel alloy is highly suitable for shaft manufacture due to the material's high torsional and tensile strength.

The hardenable martensitic stainless steel finds use in applications requiring corrosion resistance with good toughness and overall strength. Our product offers impressive saltwater resistance, making the alloy popular in marine hardware and component applications. Type 431 stainless offers good machinability once annealed, but weldability may prove difficult. The alloy should be preheated before welding to reduce the risk of cracking.


Typical commercial applications include:

  • Heat-treatable martensitic stainless steel
  • High tensile and torsional strength
  • Highly suitable for shaft manufacture
  • Impressive saltwater corrosion resistance
Supply Condition

We supply 431 stainless steel, typically hardened and tempered in the 'T' condition to achieve a tensile strength of 850 - 1000 Mpa and a minimum proof stress of 665 MPa.


The product also responds well to nitriding if tempered and pre-hardened. Nitriding affords further benefits, including additional hardness, wear resistance and improved fatigue resistance. Life cycles of finished components may be extended as a result.


431 stainless steel finds use in applications including valve stems, aircraft components, marine systems, and pump and propeller shafts.


We stock 431 martensitic stainless steel in round bars. We also offer dedicated billeting services to cut your round bars to size.

431 Stainless Steel
431 Stainless pdf
431 Stock

Product Summary

Product 431
Type Martensitic Stainless Steel
Availability Round bar
Benefits Heat-treatable martensitic stainless steel, high tensile and torsional strength highly suitable for shaft manufacture, impressive saltwater corrosion resistance
Applications Valve stems, aircraft components, marine systems, pump & propeller shafts
Datasheet 431 - Technical Datasheet
Reference Home/ Products/ Stainless Steels/ 431

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