H21 HOT WORK TOOL STEEL

 

 

APPLICATIONS

H21 is particularly useful for hot forging and blanking dies and punches for making nuts, bolts and other similar small components.  Dies, cores, inserts, pins, etc  for the die casting of copper base alloys are also prime applications for this steel.  Other uses include forming dies, shear blades, hot extrusion dies, mandrels, punches, die holders, ejector discs and extrusion liners.

 

ANNEALING

Pack preferably in a suitable sealed container with spent carburising mixture or cast iron chippings to prevent excessive scaling or decarburisation.
Heat to 850°C / 880°C, holding at temperature for sufficient time to achieve uniformity.  Cool at less than 25°C per hour to 650°C followed by air cooling.  Correctly annealed the tools or parts should not exceed 248 HB.