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403 Stainless Steel

Penn Stainless inventory includes Alloy 403 (UNS S40300) in  round bar thru re-certification of 410 stainless steel.  Other product forms such as plate may also be available by re-certifying 410 stainless steel to meet the requirements of 403.


General Properties

This straight chromium stainless steel offers reasonable corrosion resistance and high mechanical characteristics. The 403 Series offers heat resistance and a scaling temperature of about 1300°F. It is a corrosion and heat resistant 12% Cr martensitic stainless steel. This alloy offers a wide range of mechanical properties that are obtainable by appropriate heat treatments. It is easily hardened by oil, fan or air cooling and may be tempered at temperatures of up to 1350°F (732°C) to improve fracture toughness. Oil or fan cooling is required in thicker sections





  • Compressor blades
  • Turbine parts

Corrosion Resistance

  • High degree of resistance to atmospheric corrosion because of its ability to form a tightly adherent oxide film
  • Maximum corrosion resistance is obtained by hardening and polishing.
  • Not recommended for use in severely corrosive environments.

Oxidation Resistance

  • Resists oxidation up to 1400°F (760°C).
  • Temperature should not exceed 1200-1300°F (649-704°C) in  continuous service.

Hot Working/Heat Treatment

Forging or Rolling

  • Starting temperature between 2000°F and 2100°F  is recommended for forging, with a finishing temperature recommended above 1400°F .
  • Final forging temperatures as low as 1300°F, if care is taken not to rupture steel
  • Better mechanical properties obtained in forged and tempered condition in lower temperatures


  • May be annealed at 1500-1650°F, followed by a slow cool to 1100°F , and a final air cool.


  • Material may be fully hardened by oil quenching from 1650-1800°F
  • Light sections may be hardened by air or fan cooling.
  • Alloy will harden, to varying degrees, when cooled from temperatures above 1500°F


  • May be done at a temperature between 400°F -1400°F
  • Advisable to avoid the 800°F – 1100°F range due to a decrease in impact properties and corrosion resistance.
  • Strength and hardness decrease in the  800°F – 1100°F  while ductility and toughness increase as the tempering temperature is raised.

Chemical Properties:

% Cr Ni C Si Mn P S Fe
403 min: 11.5
min: 0.60 max: 0.15 max:0.5 max:1.0 max:0.04 max:0.03 Balance

Mechanical Properties:

Grade Tensile Strength
ksi (min.)
Yield Strength 0.2%
Offset ksi (min.)
Elongation -
% in
50 mm (min.)
(Rockwell B) MAX
403 70 30 25 98

Physical Properties:

Coefficient of
Thermal Expansion (min/in)-°F
Thermal Conductivity BTU/hr-ft-°F Specific Heat BTU/lbm -°F Modules of Elasticity (annealed)^2-psi
at 68 °F at 68 – 212°F at 68 – 1450°F at 200°F at 32 – 212°F in tension (E)
0.276 5.5 6.6 9.3 14.4 29 x 10^6