best stainless

[jacob7]

I am wondering what stainless metals can be used to get good results in a knife blade by just air cooling or oil cooling but with no cryo . I really have no way to cool it down. I'd like to get hardness to 58 to 60. Right now I'm working with 440-C. I don't know about the so called super steels. Thanks

[Ray Rogers]

Pretty much all the stainless we use can benefit from cryo but only the 'super steels' come with a strong recommendation for cryo. 440C is an excellent choice for air quenching. It benefits from cryo but doesn't require it. It will reach or exceed Rc 58 without cryo. I'd use it over the other stainless blade steels if air quenching was my goal and no cryo was available. Some of the super steels say they will respond to this treatment, and they do, but the response is very poor compared to other treatment methods. To my way of thinking, this makes them over priced for the performance that you can expect from the simpler treatment methods ....

[DwaneOliver]

CPM S30V is a good one, I also dont have a cryo tank , and it comes out great for me.
I do use some Alum plates to quench with.
I dont have a hardness tester, but feedback has told me they "seem to stay sharp forever"
Here is a link to the Data sheet from the Mfg.
http://www.alphaknifesupply.com/Pict...CPMS30V-DS.pdf

[Doug Lester]

When you say best you have to say best for what. Something like 440C doesn't hold an edge for ever but you can sharpen it on just about anything you can sharpen a carbon steel blade with. One of the super steels, like S30V, seem to stay sharp for ever, but they don't. Cutting up a lot of cardboard boxes with them will take the edge right off, just not as quickly as it will take the edge off 440C. Then you will need a belt grinder or a diamond hone to put an edge back on them. Which is great if you have a belt grinder handy or you remembered to pack your diamond hone with your gear. One man told me his solution was to mail his back to the factory to be sharpened and use a backup knife until his came back a couple of weeks later. Not a very good option in many cases and not all makers offer this service. These super steels also seem to be more brittle than 440C.

If you need to make your blades from a stainless steel I think that the tried and true older steels like 440C or 154CM are better choices-in general. I'm not going to be like an old gun writer who held that calibers like .270 were just a flash in the pan and they would be forgotten long after real rifle rounds like the .30-06 and the .308 were still going strong. These super steels have their applications and are here to stay, but so are the older tried and true stainless blade steels. And so are carbon steel blades.

Doug

[Gary Mulkey]

A simple way to do a cryo is to use dry ice. This normally will take 4 hours. What you will gain is a more complete austenitic conversion. Just remember to do an additional temper after cryo.

Gary