OK , I have looked at Admirals web site , I used their recomendation for the 440C , and their recomendation for ATS-34 uses oil to quench , BUT I have also heard you can do a air quench. I have also found other info for the 440C , ie temps , quenchants , times.....
I'm so confused now:confused: :confused:

There's always some variation on who likes which 'recipe'. My advice is to ask a knifemaker how to make the steel best for a knife. I send my stainless to TKS, so I can't help much. Someone here will chime in soon, I'm sure.

The oil quench for ATS-34 is a new one on me though!

More and more are using a 'plate quench' for those alloys ,I would recommend that. There are lots of postings about that .Simple , effective, no mess.

BigD: Go to the Crucible sticky link at the top of this page. Get the correct Austenitizing temperature for 440C. Wrap your blade in SS foil. Follow th recommended soak times and press quench between flat Aluminum plates. Double temper, 2 hours each time.
That is the law!

The reason the steel manufacturers sometimes recommend an oil quench for some stainless steels is for manufacturers who are quenching parts other than knife blades that have a large variation in size and thickness within the same piece of steel.

For instance, they may be quenching a piece that is 1/4" thick on one end, then has a step up to 3/4" on the other end. The large variation in thickness within the same part and the shoulder created at the intersection creates a large stress riser that can cause a crack at the shoulder. For that reason, an oil quench is recommended just to be safer. The oil helps cool the entire piece at closer to the same time rate.

For a normal knife blade, there isn't enough variation in thickness to create that problem, so either an oil, air, or plate quench will work just fine. :101

I've always used a plate quench for several reasons. The plate quenches must faster and keeps the blade areas in contact with the plates from warping. :)

Thanks guys , I appreciate the info. Don : Thanks that clear's alot up for me.