Quick Facts

Stainless Steel type 420 is a martensitic stainless steel that provides corrosion resistance similar to 410 plus increased strength and hardness. It is magnetic in both the annealed ands hardened conditions. Maximum corrosion resistance is attained only in fully hardened or fully hardened and stress relieved condition. It is seldom used in annealed condition.

Typical Applications

  • valves
  • injectors
  • fasteners

Supply Range

AMS is able to supply the following diameter range
OD 3.00mm cold drawn, ground and polished up to
OD 50.80mm cold drawn, ground and polished
Primarily manufactured in Europe,

Industry Specifications

  • AMS 5506
  • ASTM A176
  • ASTM F899

Material may also be supplied against Customer specifications, subject to enquiry.

Chemical Analysis %


Mechanical Properties


Heat Treatment

For maximum softness, heat uniformly to 1500 – 1650 °F (816 – 899 °C) and cool slowly in the furnace.
Process Annealing:
Heat to 1350 – 1450 °F (732 – 788 °C), air cool.
Preheat, then heat to 1800 – 1950 °F (982 – 1066 °C), soak at temperature and air cool or quench in warm oil.
Stress Relieving:
Heat at 300 – 800 °F (149 – 427 °C) for 1 to 3 hours, cool in air or quench in oil or water.