1400 to 1475 degrees F. Annealing, 1375 to 1425 degrees F.
TEMPERING TEMPERATURE
As Quenched 300 deg 400 deg 500 deg 600 deg 700 deg
64 62.5 60 57 53.5 51.5
HEAT-TREATMENT OF TOOL STEEL
The rate of heating for hardening should be slower for alloy steels than for plain carbon steels. The
higher the alloy content, the slower the heating rate should be. Much difficulty with warping or size
change can be reduced or eliminated by slow uniform heating.
If you have a gas furnace start the heat low, and bring up the temperature in steps. This takes about 30
minutes. Always put the tools in the oven before it is started. This preheating is not always necessary for
the water hardening or oil hardening groups, but I have found that this usually eliminates warping. I have
found also that this preheating will reduce the time in a hardening furnace without atmosphere control
and reduce scaling and decarburization.
Commercial compounds can be bought for temperatures up to 1550 degrees, to eliminate
decarbonizing of the surface Brass-brazing flux can be used also, and it works up to 2200 degrees.
The steel must be held at a temperature long enough to ensure uniform temperature throughout the
entire piece. Longer time at temperatures is required for the high alloy steels. When heating 01 or 02
steel it is best to hold a slightly rich flame on the gas furnace to keep from getting a soft skin on the
surface after quenching.
QUENCHING MEDIA
I have used quite a variety of liquids to quench the tools in over the years, here are some that I have
used
WATER
Water as it comes from the faucet, but I have not got to good results, as there seems to be too much air
in the water. If you use water, keep the temperature at 60 to 80 degrees.
BRINE
This will produce a more uniform quench if not over 10% salt by weight is added to the water. I have
found that it will produce a much cleaner and uniform surface on the tools. As with tap water,
temperatures should be held at 60 to 80 degrees. After quenching, dip in oil to eliminate rusting.