Thread: Stainless Steel

http://en.wikipedia.org/wiki/Cryogenic_hardening

Friodur Henckels employ this technique.

Nin hao ma Robert.

Agreed about purity. Realistically, from a purely historical standpoint, folding and welding occurred simple to remove the dross from the bloomed or puddled material.

And also about the speciality of the material. Compared to the high-test mill steels and the wonder alloys available, tamahagane doesn't stack up that much. As a rare material, sure there is some value not found in the more common off the rack stuff, same for wootz. But there are technically better materials to be found easier.

Arguing about semantics can refine understanding, because semantic misunderstanding is the basis for a lot of myths.

In re: cryo treatments. Any steel that is likely to have retained austenite (stainless steels, aka high alloy steels, are notorious for this phenomena and those that are subject to incomplete heat treatment practices) may benefit from subzero cooling to convert the retained austenite to martensite.

I have some issues with the apparent conflict of interest in that element of the business because most of the research about this subject is being hyped by the very folks who are in the business of selling the equipment. If it works, great, no argument from me. Personally, I don't think its worth the extra money and would prefer to heat treat the material correctly in the first place. Some steels, not all, benefit though.

It's good to see you here Terry.

Mike, incredibly informative as per usual. Many thanks .
M.

Originally Posted by Mike Blue

However, I've been using a Japanese razor, off brand, every other day for the past eight months and haven't even thought about honing it yet. It's some kinda stainless and I've been pleasantly surprised despite my normal affection for stuff that happily takes a patina. I'd bet its probably a Hitachi CPM or ATS34 type.

Could you post a pic of this razor, or give some more info?

I travel to Japan on business a couple of times a year, and would like to be on the lookout the next time I'm there...

Anyone know what is the hardness of the Friodurs or Stainless Dovos? It doesn't even say what steel it is. If it is indeed 440C, with cryo it can be as hard as 63 rc. Without cryo 58-59 rc is the max.

There was a post about three or four years ago from a member that had a Friodur tested and it came out to about 60rc IIRC. Pretty soft by razor standards, and somewhat surprising since they hone like they're harder. But they shave superbly anyway...

Originally Posted by mparker762

There was a post about three or four years ago from a member that had a Friodur tested and it came out to about 60rc IIRC. Pretty soft by razor standards, and somewhat surprising since they hone like they're harder. But they shave superbly anyway...

Good to know! Thanks!

Originally Posted by Joe Chandler

The seller (me) didn't. I said that's what I was told by the German guy I bought it from. Just clarifying. Solingen, though, like Sheffield, has steel purity laws to protect their reputations, and since there aren't that many razor manufacturers, and this one showed signs of high quality manufacturing (good, consistent grind, clean finish, nice tolerance), I'd say there's a good chance he was being straight (no pun intended) with me.

Oh! Are the these Sheffield and German steel purity laws the same as the German beer purity laws - they can't put in any additives or preservatives in the steel - and no rice either! Sheffield/German steel purity laws? Do you have any references for the here-to-for unheard of Sheffield and German steel purity laws?

Originally Posted by Mike Blue

Nin hao ma Robert.

Agreed about purity. Realistically, from a purely historical standpoint, folding and welding occurred simple to remove the dross from the bloomed or puddled material.

And also about the speciality of the material. Compared to the high-test mill steels and the wonder alloys available, tamahagane doesn't stack up that much. As a rare material, sure there is some value not found in the more common off the rack stuff, same for wootz. But there are technically better materials to be found easier.

Arguing about semantics can refine understanding, because semantic misunderstanding is the basis for a lot of myths.

In re: cryo treatments. Any steel that is likely to have retained austenite (stainless steels, aka high alloy steels, are notorious for this phenomena and those that are subject to incomplete heat treatment practices) may benefit from subzero cooling to convert the retained austenite to martensite.

I have some issues with the apparent conflict of interest in that element of the business because most of the research about this subject is being hyped by the very folks who are in the business of selling the equipment. If it works, great, no argument from me. Personally, I don't think its worth the extra money and would prefer to heat treat the material correctly in the first place. Some steels, not all, benefit though.

It's good to see you here Terry.

Please sell me all your Dubl Duck Wonderedges since the cryo hardening didn't do them any good.

Originally Posted by Eleventh

I have read that 440 stainless should be avoided, but that there is some stainless that is nice and holds an edge for a long time without much maintenance. I was hoping someone could tell me what the "nice" stainless steel is and how to tell it apart. I recently purchased a Solingen Stainless razor and am hoping it falls in the latter category. Thanks.

Both the Henckels and Dovo stainless razors are cryo hardened 440C, (per DOVO/Anne Rothstein), and I suspect that is all they use or have used for stainless razors in Solingen. There is a big difference in 440A, 440B and 440C. 440A is great for making knives and forks for the dinner table but isn't at all suitable for razors. Both 440A and B are somewhat softer and more corrosion resistant than 440C. 440C can be hardened up to to Rc 60. The only real difference though is the carbon content - 440A having .65-.75% carbon, 440B having .75-.95% carbon, and 440C having .95-1.2% carbon.