View Full Version : Tempering CK 60


Cyrus Chan
02-19-2002, 09:00 AM
Heh Ed,
thougt you might be able to help me in that. I just edge-quenched 2 blades out of CK 60. Contents are:
C: .57-.65
Mn: .80-.90
Si: < .40
Cr: < .40
Mo: < .10
Ni: < .40
I was told to temper it right after hardening and not to do a triple quench. Tempering: 3x half an hour and always quench in cold water when the blade comes out of the oven because it will be brittle after cooling in still air.
Well, I thought that I will temper it 3x 2 hours at 350 F and let it cool in still air. Am I wrong?
So, any ideas( it is a bit like 5160 with less Cr and a bit Mo and Ni and could that be the big difference?)
Thanks, Cyrus

Ed Caffrey
02-19-2002, 05:48 PM
I'd go with what you mentioned (3x2hrs @ 350F) once you get it finished, do the brass rod test and see how it reacts. If the blade chips, then temper again at 25F higher than before, and so on until it will flex over the brass rod and return to true.
The idea of quenching in cold water right out of the tempering oven scares the heck out of me! Basically the same thing would occur that happens when you try to soft back draw a blade and quench it to cool it. NOT A GOOD THING!
Let us know how it turns out.