This grade has good ductility in the annealed condition but is capable of being hardened up to 50 Rc... the highest hardness of the 12 per cent chromium grades. Best corrosion resistance for this grade is achieved when the metal is hardened, surface ground, or polished.

Corrision Resistance:
Good resistance in the hardened condition to the atmosphere, foods, fresh water, and mild alkalies or acids. Corrosion resistance is vary low in the annealed condition.

Heat Resistance:
Not recommended for use in temperaturs above 700 degrees F.

Heat Treatment:
Annealing - Heat to 1550-1650 degrees F, slow furnace cool to 1100 degrees F and then air cool. Sub-Critical Anneal - Heat to 1350-1450 degrees F and air cool.

Hardening:
Heat to 1800-1900 degrees F and air or oil cool. Oil quenching is necessary for heavy sections. Temper to obtain a wide variety of hardness values and mechanical properties as indicated in the accompanying table and graph.
NOTE: THE TEMPERING RANGE 800 TO 1100 DEGREES F SHOULD BE AVOIDED.

Welding:
Pre-Heat at 300-600 degrees F and post-heat at 1125-1400 degrees F. Type 420 coated welding rods recommended for high strength joints. Types 309 and 310 can be used if ductile weld required.

Typical Applications:
Cutlery
Knife Blades
Surgical instruments
Needle valves
Shear blades