Understanding Honyaki

Find deals on amazon
Japanese Knives - by Tokushu Knife
Kitchen Knife Forums

Help Support Kitchen Knife Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Sorry but just want to clarify are you talking honyaki in general or specifically mizu honyaki (aka water quenched).

Isn't the extra edge retention more a factor of gettin lg a slightly higher HRC with honyaki than other blades types
 
malexthekid said:
Sorry but just want to clarify are you talking honyaki in general or specifically mizu honyaki (aka water quenched).

Isn't the extra edge retention more a factor of gettin lg a slightly higher HRC with honyaki than other blades types
Click to expand...

In general... But as stated before by Mert quenching in water does allow for you it increase a blade's hardness.

You are 100% correct the edge retention is from the higher HRC, and any way you increase the hardness has this effect. The trade off is the blade becomes more brittle.
 
Yeah that is what I thought. You get the edge retention because tempering back the spine compensates for some of the extra brittleness... aka you can push the limits hrc at the edge.
 
malexthekid said:
Yeah that is what I thought. You get the edge retention because tempering back the spine compensates for some of the extra brittleness... aka you can push the limits hrc at the edge.
Click to expand...

Exactly. Ever wonder why you don't see too many honyaki knives made from Shirogami 1? Think about what the trade off between Shirogami 1 & 2 is. Higher % of Carbon in its Chemical composition than White Steel #2, which makes for more hardness, but is more brittle.
 
I'm interested as to why people buy honyakis.

Is it because of:

1) The increased hardness (but then why not just buy a harder steel?).
2) The beauty of the blade.
3) The fact that it's made by an artisan who really knows their stuff and loves their work. So all of the other aspects of the blade should be great too.
4) The fact that the artisan has poured his (I assume there aren't many ladies making honyakis- apologies if I'm wrong) heart and soul into making the blade.
5) The rarity/ exclusivity.
6) Thy mystique of honyakis.
7) The fact that the blade you have is one out of 2 or 3 or more that actually made it without pinging when being quenched.
8) Some other reason.

I guess for me it's mainly 2,3,4 and 7, with a little bit of 5 and 6 mixed in.

Interested to hear your thoughts.
 
BTW, can/do smiths make a smaller blade (or two :) out of a large honyaki blade that blew in half during quenching, or does the fact it blew already show it was f....ed steel in the first place?
 
Because they are alive, they have soul, and they talk to you when you use them (through their feed back)

Plus all the reasons that you mentioned, which come to think about it, aren't they more than enough?

I fell in love with Honyaki at first look and touch.
I was cautious... After the first cut, no doubts
 
chefcomesback said:
Also keep in mind honyaki knives are forged different than San mai and heat treated differently too , I am talking about true forged clay quenched honyakis not stock removal edge quench ones they appear " Honyaki "
Click to expand...

I am clueless about the technicalities involved.
Can you please explain in a quick and simple way, the forging stage differences and the heat treatment stage differences?
Or post some links, if possible?

Thank you very much in advance!
 
supersayan3 said:
Because they are alive, they have soul, and they talk to you when you use them (through their feed back)

Plus all the reasons that you mentioned, which come to think about it, aren't they more than enough?

I fell in love with Honyaki at first look and touch.
I was cautious... After the first cut, no doubts
Click to expand...

Yes, they are more than enough. I guess I was wondering which of those reasons were more important to other people.
 
supersayan3 said:
I am clueless about the technicalities involved.
Can you please explain in a quick and simple way, the forging stage differences and the heat treatment stage differences?
Or post some links, if possible?

Thank you very much in advance!
Click to expand...

I'm also interested in this. Not asking you to divulge any trade secrets though. 😃.
 
supersayan3 said:
I am clueless about the technicalities involved.
Can you please explain in a quick and simple way, the forging stage differences and the heat treatment stage differences?
Or post some links, if possible?

Thank you very much in advance!
Click to expand...

Explain quick and simple ? It took me reading 2 reference books one in heat treatment one in Japanese swords , break $$$$ worth steel , test tons of blades in shop and in pro use in kitchen and come to my conclusions , I doubt there is a simple link explaining it all within few sentences
 
chefcomesback said:
Explain quick and simple ? It took me reading 2 reference books one in heat treatment one in Japanese swords , break $$$$ worth steel , test tons of blades in shop and in pro use in kitchen and come to my conclusions , I doubt there is a simple link explaining it all within few sentences
Click to expand...

Sounds like too complex a topic for simple explanations. I must say this does not suprise me. Maybe that's part of what that contributes to the beauty of the end result.
 
chefcomesback said:
Explain quick and simple ? It took me reading 2 reference books one in heat treatment one in Japanese swords , break $$$$ worth steel , test tons of blades in shop and in pro use in kitchen and come to my conclusions , I doubt there is a simple link explaining it all within few sentences
Click to expand...

Bravo!
You are a lover and a believer!
Keep on going!
 
I like mono steel knives more than clad. Don't know why except the mono knives stay and the clad ones go.
When you start down the Honyaki road you must make sure value is not a priority for you.
 
Nemo said:
Sounds like too complex a topic for simple explanations. I must say this does not suprise me. Maybe that's part of what that contributes to the beauty of the end result.
Click to expand...

Not to mention that you are holding something that it takes probably thousands of hours to learn how to make...
 
Chuckles said:
I like mono steel knives more than clad. Don't know why except the mono knives stay and the clad ones go.
When you start down the Honyaki road you must make sure value is not a priority for you.
Click to expand...

Wow, that's very interesting. I've recently repurchased a ks(for the 3rd time) and I find myself digging mono for a few reasons. I hate to get off topic so maybe we can PM but I'd like to see a list of your fave mono(non honyaki) gyutos.
 
Nemo said:
I'm interested as to why people buy honyakis.
Click to expand...

A lot of the cost and allure of the hamon have to do with the fact that manifests itself as a visible line in the steel - a line which is hard to control where it ends up, and if done well showcases the smiths understanding and control over the steel and its properties.

When quenching these kinds of steels (fast/shallow hardening steels as opposed to slow/deep hardening steels) forming martensite can be thought of as an on/off switch: You get it or you don't, and it's mostly dictated by a controlled drop of temperature (about 250-300°C within the first second of the quench). This is difficult to do accurately, and the outcome will affect the look of your hamon.

Nemo said:
Can you dictate the pattern of the hamon by where you put the clay? Or is it less exact?
Click to expand...

The random patterns which are easier to create, as minor imperfections wont show up in a random pattern.

13398561_1017840744935735_1346153106_n.jpg


Then there are repeating patterns which take more control.

e1fe21e66806f152dcb59abfb1109236.jpg


Whichever one looks better is totally up to your individual tastes.
 
Kippington said:
When quenching these kinds of steels (fast/shallow hardening steels as opposed to slow/deep hardening steels) forming martensite can be thought of as an on/off switch: You get it or you don't, and it's mostly dictated by a controlled drop of temperature (about 250-300°C within the first second of the quench).
Click to expand...

Are the deep/ slow hardening steels what are referred to as highly hardenable steels (usually with a few alloying elements from memory). Does the hamon rely on not having high harden ability in the steel (or am I completely on the wrong track here...?)

If they don't form Martesnite (and I assume we are talking about the softer steel here), do they then form pearlite grains or do they form cementite in the grain boundaries and ferrite inside the grain or does it depend?
 
I always thought low hardenability meant possible hardening depth in inches vs feet for highly hardenable alloys?
 
Yes, I think that's the same concept that I'm referring to. As I said, I'm not sure I'm on the right track with this line of thought.
 
Nemo said:
Are the deep/ slow hardening steels what are referred to as highly hardenable steels?
Click to expand...
Yep you are right.

The problem with fast/shallow hardening steels is that if you take something large (lets say, a 100kg sphere of Shirogami #1) and quench it in water, the centre of the mass won't cool down anywhere near fast enough to harden. Only the outside cools fast enough to create martensite, whereas the inside has too much thermal mass to cool fast enough (there is no way it's going to drop 300°C in one second) and so pearlite begins to form before martensite gets its chance. This explains why they are called shallow hardening steels, as they wont harden in thick cross-sections.

We use this seemingly negative property of shallow hardening steels to create hamons. As most people know, the most common way to create a hamon is to coat the spine in clay. Doing this keeps that part of the steel away from the quenchant, allowing it to hold the heat in for long enough that soft pearlite comes into play before the hard martensite has had the chance to form.

Deep hardening steels don't form pearlite anywhere near as fast: meaning we can drop the temperature at a much slower speed and have the entire thing turn into martensite before it has already become pearlite. Some steels can be quenched so slowly that still air is fast enough to harden them. Other steels won't even harden and are stuck as austenite all the way to room temperature - the ultimate 100% retained austenite!

This is not to say that it's impossible to create a hamon with deep hardening steels, it would take a lot longer though...

***I should also mention that shallow hardening and deep hardening steels can both end up at the same hardness. Hardenability is not the same measurement as how hard a given piece of steel can get, but how quickly or slowly it gets there.
 
Thanks Kippington. That makes sense.

To paraphrase: If the steel doesn't cool to its MS point before a lot af pearlite has formed, it will be soft, but if it does, it will be martensitic and hard. From memory, there are some temp vs time curves that describe this aren't there?
 
You might have to explain this a bit more. You're saying the reason they differentially harden is to allow the smith a means more easily bend the blade back to straight. But being differentially hardend is the reason they are more likely to warp, and warp more severely. The more bending you have to do post heat treat the more likely you are to break the blade. Also, i don't see many hamons dividing more than 40-60% of the blade so if there's a warp closer to the edge or toward the tip, a hamon at the spine near the handle isn't going to help much.

I would have thought the hamon was a show of skill in that inspite of the higher risk of warping during quench and inspite of the greater risk of damage during straightening the blade made it through. Mitigating warping is One of the challenges in both fully hardened and more so in differentially hardend blades. A hamon is like a receipt of skill captured in the metal.

bkultra said:
Ok as a Honyaki owner myself I will take a stab at this. First a honyaki will not hold an edge any longer than a blade made of the same steel and same hardness. Second the hamon is a byproduct of needing a way to be able to straighten out the blade after it's been quenched. Mizu (water) honyaki are mono steel knives quenched in water and they have a very high failure rate because the blade tends to warp when quenched... Hence the need to straighten it. The hamon is purly cosmetic.

In regards to knives, honyaki blades helped single beveled knives from warping as well... Their purpose and benefits on double beveled knives is up for debate.
Click to expand...
 
You must log in or register to reply here.

Latest posts

Back
Top