Stainless 420

Annealing Procedure

1550-1650 F (843-900 C), slow furnace cooling.

Applications

Dental and surgical instruments, cutlery, pump shafts, plastic molds and dies, steel balls, and various hand tools.

Cold Workability

420 will withstand only minor cold work. Radical forming operations will result in cracking.

Hardening Procedure

Soak at 1850-1950 F (1010-1066 C) at quench in heated oil.

Hot Workability

Bring temperatures slowly up to 1400 F (760 C), then on to 2000-2200 F (1097-1204 C), after working, furnace cool slowly to avoid cracking. Reheat often to keep the working temperature above 1600 F.

Machinability

Similar to machining some of the high carbon tool steel, this alloy has tough, stringy chip build-up.

Principle Design Features

This alloy is a general purpose heat treatable chromium steel which is a popular cutlery grade.

Tempering Procedure

300-400 F (149-204 C), air cool for maximum hardness and corrosion resistance.

Weldability

Not commonly welded due to its air hardening characteristics. Welding may be performed after preheating to 300-400 F (149-204 C) with post weld tempering at temperature for 2 hours . Filler metal should be AWS E/ER420.