Honyaki question

Hi all, a quick question on honyaki and differential hardening.
It's generally understood that honyaki is differentially hardened carbon steel, usually with either of hitachi white or blue, or even steels like v2

I was just wondering if differential hardening was possible with stainless steels.
In sakai there are blades sold as honyaki, but realistically they are zenko knives, or simply monosteel, with no differential hardening whatsoever.
Can you technically perform differential hardening with water or oil quenching on a stainless steel with a full hamon line?

It's very difficult (not possible?) to differentially harden stainless steels due to the hardenability of highly alloyed steels. Hardenability is a metallurgy term referring to the ability of a steel to harden at some distance or depth from the interface between the steel and the quenchant. it becomes important when hardening thick pieces of steel but also affects the ability to differentially harden.

Stainless knives labelled "honyaki" may or may not be be cryo treated monosteels. IMO, these are not real honyakii. It seems to me like a marketing term in this situation. Having said that, many of them are reputed as very good knives.

I have seen loads of threads on knife making forums about oil/water (but typically oil) quenching stainless with fair results. So I guess theoretically you could differential harden stainless that way. But I have no idea just remember a few threads I have seen in the past with zero practical experience.

http://www.kitchenknifeforums.com/s...tainless-steel-honyaki-and-a-hamon?highlight=

This thread links to yet another thread with more info

That is an interesting read although a bit short.

You can differently harden many stainless, but I have never seen a hamon.

RDalman said:

You can differently harden many stainless, but I have never seen a hamon.

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https://www.haslinger-knives.com/differential-tempered.html

Isn't differntial tempering quite different to differential hardening?

My understanding is that in differential hardening, you are taking a hot chunk of steel which is austenite and quenching it in such a way that part of it (the edge) forms martensite and part (the spine) forms much softer, much tougher pearlite.

In differential tempering, you are taking a blade which has already been quenched to be fully martensite and you are tempering some of that martesnite (near the spine) so that it is a little softer and a little tougher, but still martensite.

Let me know if I have it wrong.

I have a very vague understanding of this but why not only partially submerge the blade in oil, for example. I have seen fellows do that on youtube. Would that not suffice in hardening the edge more so than the spine? Granted, I know we are talking about air hardening steel here, and I am a few beers in, but idk...just curious.

Yea kit is on track. The hardness difference will not be huge but it will be there for some steels.

Suisin Inox Honyaki??? Hmmm...... :scratchhead:

cheflarge said:

Suisin Inox Honyaki??? Hmmm...... :scratchhead:

Click to expand...

no.