The development of ever-larger plastic parts places increasing importance on the correct heat treatment of the moulds. In order to eliminate dimensional changes and quench cracking, pre-heat-treated steels are used for large tools. They are heat-treated to a hardness of 290 – 400 HB / approx. 30 – 43 HRc by the manufacturer. At this hardness, the steel retains its good machinability but still has a good wear resistance and adequate strength.
Particular advantages of pre-heat treated steels are:
- No need to heat treat after machining
- Can be used as supplied even in large dimensions