Do I need to temper?

[huntforlife]

Got my blades back from Tx. Had them heat treated and cryo treated. Do I need to temper them still? Or is the cryo actually the temper?

Am finish sanding them now, so dont want to go to far without knowing what all to do.

[pipecrafter]

Heat treating involves tempering, the cryo is an add-on that you can get IN ADDITION to quench and temper (heat treating). If you sent your knives to Texas Knife, they tempered them for you.

[huntforlife]

Ok thanks Kurt. I finally got ahold of them and the said the same.

I was confused, because on the order form it had tempering as an option, so I wasnt sure if it was done or not.

Thanks again.

[WBE]

That is a strange option to offer for heat treat, unless they mean to what hardness you might want. That has to be what they mean by that.

[pipecrafter]

Oh, interesting. I wonder if they do mean to a specific tempered hardness, as WBE said. That would make more sense. Tempering pretty much is not optional for a correct heat treat.

[huntforlife]

Well originally, I was under the impression that heat treating, ie. wrapping in foil and heating to whatever temp for so long, was the first step. Once that was done, I thought you were supposed to heat it a lower temperature and fast quench it to temper it. I thought if you just heat treated it the metal would be to brittle. I thought tempering made the metal margenite or whatever its called.

[pipecrafter]

You heat to a high heat then quench. Specifics depend on the steel, and differ greatly. Then you heat to a lower heat and hold for at least an hour. Sometimes multiple times. Again, specifics vary by steel. Stainless steels are vastly different from plain carbon steels, or even tool steels that have carbon as the main alloying element but may contain other elements like chromium.

Here it pays to become very familiar with a given steel and learn how to heat treat it for best results before moving on to another. I started off with 01, then moved into the 10xx steels. Now that I heat treatment of these down, I plan on experimenting a bit with the higher end stainless like the CPM steels.

[mete]

Once hardened it MUST be tempered and if Cryo'd it MUST be tempered afterward.The tempering is done by the heat treater.

[huntforlife]

Thanks guys.

Hey, whoever it was that talked about the WD40 wetsand in another thread, THANK YOU!

I think all of my knives will now be done to 600 with WD40. Not mirror, but not to dull.

[lpspurgeon]

So what do you miss if you do not do the second tempering ? I bought some cpm154 and dog gone it I forgot the second dose

[mete]

Simple steels do fine with just 1 temper. More complex ones require 2 or 3. Something like CPM154 should have at least two. The complex steels have retained austenite after hardening.The first temper transforms most of this to UNTEMPERED [brittle] martensite. This new martensite must be tempered !