D2 Tool Steel


D2 is an air hardening tool steel. The chromium content makes it "almost" stainless. It can be quenched in still air but most knifemakers quench between two 1" thick aluminum plates. It needs to be heat treated in an oxygen free environment. This can be accomplished with blade coatings, foil wrap, or environmentally controlled kilns. It is a popular steel and makes good knives. The following process is a good starting point for heat treating D2. Your equipment may require different temps. & times so feel free to experiment.
1. Heat to 1100-1200 and equalize.
2. Heat to 1400-1450 and equalize.
3. Heat to 1825-1875 and soak for 30-45 miuntes.
4. Quench in air or between quench plates to 150 degrees.
5. Temper twice for 2 hours each time. Temper between 400 & 1000 depending on the application.

D2 benefits from a sub-zero freeze or liquid Nitrogen cryo but it isn't necessary. If either is used it must be followed by a tempering cycle.


Well-Known Member
My guess is he meant normalize. bring it up to temp and bring out and let cool to black color... bring it up to temp and let cool to black. Its a stress relieving method.

Normalizing is a different process. When I say equalize, I mean let the kiln "settle" at the target temp. before moving to the next temp.. You could also just do a 5 min. soak at each temp. to be sure everything is equalized.


Well-Known Member
The big reason for equalizing and preheating is to minimize thermal stresses due to different temperatures within the same piece. Another reason is rapid heatinreg will temporarily increase the critical temperature. Rapid heating without time for equalization can result in incomplete austenization. I dont know the numbers, and I dont think its much to worry about, but it does happen. I suspect its really only an issue with things like induction hearing or salt heating. IMO, this goes beyond the scope of this forum, and can be continued in the heat treating forum if anyone wants to do so.

Joel Brazzoni

Well-Known Member
From my limited experience Cpm D-2 is really nice to work with, it grinds fairly easy, takes a nice polish and holds an edge better than 0-1 at the same hardness but is not as tough.
I think it's a great steel for smaller knives that won't see impact.
I'v had a critical failure on a large chopper with Aristocrat D-2 at 60rc.

Andre Grobler

Well-Known Member
Depending on how thick the linerlock is i would temper to 400f so that it fails plastically not brittle, but i think more important would be to use the lower austenitization temps and make stress risers very very gradual... but this is purely from a theoretical point of view and not an experience point of view... the other questiin is do you cryo or not? On second thought it makes no difference unless you temper high... in which case it is probably better not to do it... toughness for these class of steels are higher in the low temper zone... my blades get cryo and tempered between 300 and 350

Samuel G Chapa

New Member
So as to make a decent working blade, one needs a decent bit of steel. in market there are so many D2 blades available.

instructions to check the steel is D2 or not:

you can take the two absolute best D2-bladed rope cutters I have tried and think about them by cutting the neck off a plastic drink bottle. One can achieve this cut with a solitary cut. Alternate requires 15 cuts. For this situation, the diverse warmth medicines accomplish distinctive carbide grain sizes and the bigger carbide grain obviously cuts plastic superior to the nano-grain carbide, which is 10 times littler.

There are no terrible D2 blades, albeit some may suit certain applications superior to others. You choose for yourself which D2 cut suits your necessities best.


I try to search stuff on here but it takes me FOREVER to find it again...or for the first time. Now i copy and paste it to paint so I can search it on my computer as a Jpeg. here's my latest...(normally I do not post them...lol.) I saw this recipe a while back and couldn't remember who created it...so my piece of D2 has been sitting...Lol.

D2 by Darrin Sanders.jpg