420S37

Stainless Steel

420S37

British BS 970 stainless steel 420S37.

Chemical Composition (%)

C0.2
SI1
MN1.5
CR12
P0.06
S0.03

Applications

International high-end steel grade for aerospace, oil & gas, defense or engineering machinery.

Available Forms

Bar, plate, sheet, tube, forgings, strip, wire, powder

Uses

Martensitic stainless steel combining moderate corrosion resistance with high strength and hardness after heat treatment. Used for cutlery, surgical instruments, turbine blades, valves, pumps, fasteners and bearings in mildly corrosive environments.

Heat Treatment

Annealing/quench from 980–1050 °C (oil or air) then temper 150–650 °C; lower temper gives higher hardness, higher temper improves toughness.

Precautions

Preheat and post-weld heat treat to avoid hydrogen cracking; soft anneal before heavy machining. Lower corrosion resistance than austenitic grades — not for strong chlorides.

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