HTS: Guide to Heat Treating Steel for knife and tool makers

D2 Tool Steel

Heat Treating D2 tool Steel

To begin... wrap the piece in stainless steel tool wrap and leave an extra two inches on each end of the package (This will be for handling purposes). The foil should be double crimped around the edges. Note: be careful to not tear or puncture the wrap!

Once wrapped place in the furnace and heat to 1850F. Upon reaching this temperature immediately begin timing the soak for 15 to 20 minutes. (Soak time is the amount of time the steel is held at the desired temperature; which in this case is 1850 degrees Fahrenheit)

Note: soak times will very depending on steel thickness. See formula at the bottom of page.

When the soak time is complete, very carefully remove the entire package, and place it on a wire rack allowing it to air cool. Once the piece reaches 125F begin the temper process. To temper the piece remove it from the foil wrapper and place it back into the furnace at 950F allowing it to soak for 2 hours. Then remove the piece and allow it to cool to room temperature.

Tip: Open the oven door and let it be cooling to 950F while the piece is cooling to 125F.

To begin the second temper place the piece back in the furnace and soak for 2 hours this time at 900F. Once this step is complete remove the piece and allow it to cool. It should now be approx hardness 58-60 RC. 

Tip: The piece can be placed in dry ice for an hour this will add some stability and a little extra hardness.

Note: Pre quench soak times can very to some degree. However, commonly one can figure about 1 hour of soak at hardening temperature per inch of steel thickness
1 inch = 1hour 

1/2 inch = 30mins

1/4 inch = 15mins

1/8inch = 7.5mins