H13 HOT WORK TOOL STEEL

Tempering should be carried out as soon as possible following completion of quenching.  Heat to within the 550C / 650C range soaking at temperature for one to three hours according to section.  A second temper holding at temperature for at least one hour is essential and care must be taken to ensure that the tools cool to room temperature between cycles.  For applications where thermal fatigue is of prime importance a third tempering operation is recommended.  The curve given provides typical hardness values obtained on air cooling from 1020C and double tempering.