Grade 420 is a “descendant” of the martensitic grade which was invented by Harry Brearley in Sheffield in 1913. It is a hardenable stainless steel used for its basic corrosion resistance, high strength and wear resistance.
Approximate Composition – 12% Cr (exact composition ranges vary between EN and ASTM standards). The EN system defines several grades which fit into 420 by narrow ranges of carbon content whilst the ASTM system defines 420 with 0.15% minimum carbon only.
This grade combines the following characteristics:
• Basic corrosion resistance
• High hardness and strength
• Controlled balance of mechanical properties by hardening and tempering
• High wear resistance
• Cost effectiveness due to low chromium content and absence of nickel
• Thermal expansion comparable to carbon steel
• Not easy to weld
Typical applications include:
Cutlery blades, solids handling, surgical instruments, plastic moulding, drive shafts, bearings, gears, springs, conveying equipment, cargo handling, tools, seaweed driers.
420 is a great choice for basic corrosion resistance, good strength and wear resistance.