Cryogenicly treating a forged blade

SamuraiDave · Jan 11, 2002

Can you cryogenicly treat a hand forged selectively tempered blade?

I have a kukhri that currently needs a handle, and I figured that if I was going to experiment with it why not do something different.

Yes, there is something to be said about leaving well enough alone...but I am curious. I realize that, as a friend said in another forum, "the structure might be so diverse due to differential hardening, packing, etc., that the stresses of the temp drops might be damaging."

What do yall think?

Ed Caffrey · Jan 11, 2002

Sure! I do it all the time. Multiple edge quenched 52100, when cryo'ed will realize a 10-15% increase in cutting ability base on like tests on 1/2" hemp rope.

Danbo · Jan 11, 2002

I have heard different views on the cryo treatment issue. Some people swear by it, some say it does little good. I have even heard that the effects are only temporary. I myself, believe it works on just about every type of steel and that it has more effect on certain steels than others. One thing I have never heard or read is that it damages the steel. I dont think cryo is going to hurt your blade at all.

Coonskinner · Jan 12, 2002

I believe I have read that Ed Fowler cryos his blades. If memory serves me correctly, he documented a marked performance increase after cryogenic treatment. I think it's a good thing. Marbles cryos their blades, and there is NOTHING wrong with the way they perform.

TLM · Jan 12, 2002

Cryo quench should take care of most retained austenite turning it into martensite, so you could gain something in hardness and lose (maybe) something in toughness. Temperature difference itself is not that much but don't hit the blade in any way when it is cold. The blade should be tempered as after any quench (if it had retained austenite otherwise nothing happened).

TLM

Mike Hull · Jan 12, 2002

The cryo treatment is a win-win situation, you lose nothing in toughness, or anything else,you gain in every way. There is not too much made of steel that wouldn't benefit in some way from a cryo treatment, knife blades, firearm barrels,transmission/rear end gears, axles, on and on.

SamuraiDave · Jan 12, 2002

Thanks guys,

I have another question.

Where is the "best" place to have this treatment done?

I have heard about Texas Knifemaker's Supply, and Mr. Paul Bos. (However I do not know how to contact Mr. Bos.)

Where else should I look into?

peter nap · Jan 12, 2002

I'm going to step very carefully here because you've already gotten far more knowledgable opinions than mine....I Have tried true Cryo treatment and to does appear to increase the cutting ability. I tried a cold treatment on the advice of a knifemaker whom I respect very much. Just froze the thing between quenches and temper cycles.

IMHO, this freeze treatment works just as well as the Cryo dip. No matter what though, it sure doesn't hurt.

TLM · Jan 13, 2002

There is no such thing as free lunch, when you transform austenite you loose a ductile phase and that in most cases equates with toughness (which is not a very well defined term).

TLM