A Yanagi Ba for a friend

[John Cahoon]

Greetings all, I have been asked by my retired business partner to make him a yanagi ba. I've never made kitchen cutlery but plenty of outdoor styles. I've done a fair bit of research here, including Master Stacey's WIP from 2012 (can post a link if you want). That handle is a masterpiece.

I'm planning (only in my head so far) on about 7.5-8" blade with 4.5-5" handle, plungeless grind, chisel ground on the right with very long belly and long convex clip. Sort of like this commercial one from the big web:


I'm leaning toward an octagon handle with ebony up front, then leopardwood and ebony pommel all held with internal pins (need to learn the proper Japanese terms for these handle components). I'll be visiting a sushi place here to examine a professionally used version pretty soon.

So I have several questions:

Steel Choice: I'm thinking 1.25" tall is about right? Should I go 1/8" or 5/32"? What type of stainless and carbon would be good choices? I'm leaning towards carbon since I know the customer will take good care of it and have read it can get sharper than SS. I'm going to get 48" bar stock so I can make about 4. I usually hand sand after 220 belt grind up to about P400/600 prior to HT, then I might take it to p1500 or p2000 afterwards.

Edge thickness pre HT: is .02 too much? how thin can I go without risking edges warping in HT for a given steel choice?

Edge post HT: is less than .01" behind the edge capable of getting sharp enough to do the work? Is there a benefit for a secondary tiny bevel on the left side as well?

Wooden case: what's the name of the wooden sheath again? I need to write stuff down more.

Thanks in advance for the valuable help.

 

[DevinT]

These are complicated knives to make. Your current dimensions are not big enough. These are concave on the inside and ground to zero at the edge.

These require straightening out of the quench and can also warp during grinding and polishing. There is a distal taper to the blade. To sharpen one is also tricky.

Hoss

 

[Stacy E. Apelt - Bladesmith]

As Devin said, Yanagi-ba are longer and have urasaki on the back. The edge is ground to a zero edge.
Blade is usually 10"/240mm. Tsuka is about 6"/150mm.
3mm/.125" would be right for thickness.

Your blade description is more like a large petty.

Yanagi-ba means "willow blade".
The sheath is called a saya.
The handle is a tsuka.
An octagonal tsuka is called a "wa" handle. ( other common shaped are "D" and oval)
The front piece on the tsuka is a fucchi.
The back piece on a tsuka is a kashira.
The cutting edge is the ha.
The line where the edge bevel meets the upper bevel is the shinogi.
A single bevel blade is called kata-kiri-ha zukuri, often just called katakiri.
The back side shallow hollow grind is called urasuki.
Leaving an unfinished rough area above the shinogi is called kuro-uchi
There is a japanese glossary in the Stickys with knife terms.

If you use the google custom search engine in the Stickys you can pull up lots of Yanagi-ba build threads.

 

[John Cahoon]

Thanks Fellas, Stacey I should have started with the mega-sticky but didn't. My bad, Only had the zknives Japanese Knife Anatomy diagram that called the handle "handle"LOL. This is perfect. I've been to a number of wips and will be reviewing throughout the process. I always enjoy a new challenge. It might be a hybrid (or horrible mutant) but I think I can pull it off somewhat respectable. I'm leaning between Aldo's AEBL or 52100. ETA I've been using Paul BOS for HT...very satisfied. Any preference or another that may be better?

Devin thanks for the advice. Would it be possible to superglue the urusaki to a flat piece of oak to minimize warp while grinding the katakiri pre and post HT? If I did that I'd dip every pass or 2. (we're gonna need a bigger bucket.) Figured I'd start at 80 grit?

 

[Stacy E. Apelt - Bladesmith]

I would suggest making a gyuto or petty. They have a double bevel and are simpler to make. This eliminates the urasuki, which is a trick to grind without special equipment.When grinding any blade, I find it easiest to use a grinding magnet. I make a pass or two, dunk the whole thing in the slack tub, and right back to the belt.
.09 to .125 is good for stock thickness.

Supergluing it to a wood backer would not last more than a few minutes ... if that long.

 

[John Cahoon]

Great advice Stacy, I think I'll do the gyuto first and see how it goes. Since I've never done kitchen types before I'll be doing mild steel mock ups first also and see what happens. Should be a blast. I just got back from a sushi shop and the guy was very helpful, showed me a lot, including sharpening on a waterstone (don't have any yet) and let me watch him work for a bit. A commercial grade blade, it was indeed very long, about .125" thick with distal taper, a very subtle urasuki and decently made saya too. Great to actually handle one and get a feel for what's really happening.

 

[Rhinoknives1]

My 2 cents is,,, ask your buddy if he likes those Wa handles? Then size it accordingly. I personally don’t care for those Wa and put a standard Euro Birds head type handle that most of here prefer .. I have large hands and long fingers so It really taught me focus on making the handle sized to each of my customers because most don’t fit me... Stay safe & have fun!

 

[Brock Cutlery]

I have made a few. They are not fun, except and unless you really enjoy a very difficult challenge and steep learning curve. First kitchen knife? Yikes.
If I were in your shoes John, knowing what I know now, I would buy your friend a nice Yangi and figure you got off easy.

But if you do take it on, I hope you'll post WIP. You are not shy about asking for help, that is good. You will need it.
Go with 52100. Less warping issues than AEBL on that long blade. HT before grinding is what i would do. If you grind the bevel first it will likely arch in HT.
Be VERY careful not to overheat the edge as it gets thin in the chisel grind. And watch the tip. It will burn if you look at it funny.
Start with a flat blank.

 

[Stacy E. Apelt - Bladesmith]

A gyuto can have a standard western handle like Lawrence prefers. With a double bevel and a westen handle you have a lot more chance of success.

I would use .090" 52100. Hitachi blue #2 would also be a good steel if you have it available in sufficient size.

My personal preference would be S35VN. It rivals most any carbon blade in sharpness, and exceeds in edge retention. S35VN at Rc 61-62 makes superb kitchen knives.

If you had a bit more experience I would also suggest Suminagashi from Dictum.
Aldo also has laminated steel with a carbon core, but it is pricy. A 24" piece of .094X2" with 401 cladding and 52100 core runs about $200. It definitely isn't for the newbie.

 

[timos-]

I would not suggest a san mai type for a very long thin blade, 2 of my last knives were 270mm k-tip style gyutos in aldos 3/32 thick clad 52100...It was absolute hell keeping those blades straight as I could. The problem is applying pressure while grinding without bending the blade is very difficult. You could use a board backer like is often done in Japan but then you cant see too well whats going on.

The next ones I am doing are mono steel with about 50% of the grinding done post heat treat.

 

[John Cahoon]

Thanks for all the great advice! I'm going to start with Stacy's idea of a Gyuto build first, pretty sure I can pull that off, then decide from there. Of course I'll do a mild steel grind first to get a feel for working with thinner stock. I've been needing to make a few filet knives anyway.

I've settled on 52100 in .0937 or .125 and will get some of both. I'll try timos idea of only 50% pre HT, and will try an unglued wooden backer, with the tang clamped to the wood just to see if that helps any.

Laurence, I will consult with customer on handle preferences. In the past I've asked for penciled outlines of people's hands and calibrate to mine. I thought about Brock's advice (I did consider buying one after the first couple of replies here LOL) among all the others and getting cold feet plunging into a pool too deep. I still plan on a Yanagi eventually, just not the first one, and it's never really been my intention to focus on culinary work but some of the ones I've seen here are stunning.
Who knows, it might pull me in an unexpected direction.

 

[skillgannon]

A gyuto can have a standard western handle like Lawrence prefers. With a double bevel and a westen handle you have a lot more chance of success.

I would use .090" 52100. Hitachi blue #2 would also be a good steel if you have it available in sufficient size.

My personal preference would be S35VN. It rivals most any carbon blade in sharpness, and exceeds in edge retention. S35VN at Rc 61-62 makes superb kitchen knives.

If you had a bit more experience I would also suggest Suminagashi from Dictum.
Aldo also has laminated steel with a carbon core, but it is pricy. A 24" piece of .094X2" with 401 cladding and 52100 core runs about $200. It definitely isn't for the newbie.

Sorry to get off topic.
Stacy do you prefer S35VN over AEB-L or is it a apples to oranges thing?
I have 2 AEB-L knives that I made and enough steel for about 50 more. I really like the steel but have not been super happy with the edge holding. Not that it is bad it's just not the best. Maybe a bit better than 1084. Don't get me wrong, I love that screaming sharp edge both of those get its just when I am not the only person using them I have to sharpen all the time.

PS. Yes I am ask how wife resistant the steel is. I hope Larin adds this column to his charts soon.

 

[joedhiggins]

Don’t worry too much about the Wa. I find them a good deal easier than a similarly nice full tang, and they look great (I also prefer hidden tangs overall).

Basically only tool you need is a grinder, drill, and maybe a mitre saw.

I think I posted my method a while back, but if I didn’t, I can talk you through a simple method.

Here is a Wa D i did recently. About an hour ignoring the epoxy cure time.

https://i.imgur.com/yDdDM3s.jpg

 

[John Cahoon]

Hi J joedhiggins , thanks for the offer, I'll likely be asking about that in several weeks. I've got more reading to do but the 52100 is on order and I may be able to get/grind some thin mild steel in the next few days.

 

[Stacy E. Apelt - Bladesmith]

S35VN is miles ahead of AEB-L.
Edge retention is very good. At Rc60-61 it is great in the kitchen.

 

[John Cahoon]

Well, here goes. I got some mild steel from the hardware store just to see what would happen. It was cupped, bent and twisted, but I learned what I needed to know and decided to jump right in. Got the Baron’s 1/8” x 1.25 52100, very clean surface and very straight so I profiled out two as is my habit. I ground a couple of standard outdoor styles first to see how 52100 grinds and it was pretty easy.

I built a wooden jig to hold it flat to the platen on the 12 degree work rest so as to reduce bending. The bevel side is ground at 40 grit to about .05” at the edge and about halfway up to the eventual shinogi line, so that ratio should work out. It bent slightly anyway but was easily straightened on a bench corner by hand.

I talked to the pro HT and he said he’d be good if I took it to .03” but I’ll likely leave the edge a bit thicker and finish the bevel post HT. The length (nagasa) is about 10.5” from heel (???) to tip (yokote) and maybe 14” OAL to end of tang. I plan on leaving the tang flush to the ricasso for now, and will taper post HT.



My issue has always been the hollow grind on the back side (urasuki) since I have no set up for that. A light bulb went off when I noticed the curved handle side of the rubber sanding block. It’s a 9” diameter curve so pretty small from what all here have said but it seemed to work OK.

I found a great picture here of Brock’s urasuki where the lighting really made it stand out so I had a baseline. I also read a post where someone said they did it by hand so I thought that’s possible. I really don’t mind hand sanding at all, just tune out and go.

I built a sanding bed as shown. The trick here is to make the rails higher than the blade so when you start it’s only sanding the wood rails, creating a bedding curve by the time the block touches steel. Started at 40/50 grit, didn’t skip any grits so 80/120/150/ and now sits at 220. I cross sanded at 220 on the flats. That’s only a couple of hours work and I can clearly see nice even light under a carpenter’s square. I’ll be aiming for 400 grit all around pre HT, even though I’ll have to go back up to finish the bevels.




So here I am, sorry for the lengthy read, please tear it up and let me know what I can do better from here on or any fatal flaws. I have very thick skin so don’t hold back. I really appreciate the feedback.

 

[Brock Cutlery]

Looks alright! If I were to suggest a change, it would be the curve up to the tip. It is too sharp IMHO. Reduce that sharp rise. Bring it back gently maybe a third of the length. Others might suggest more.
You might be killing yourself with that deep urasuki as well. You can make a much gentler urasuki using a cut out of oak for a sanding block. A 36 inch or more is quite adequate and you'll save yourself a lot of sanding to depth.
Smart to leave a lot of meat before HT. The odd asymmetrical grinds can cause bows, arches, etc...

I have to say I admire your gumption.

 

[John Cahoon]

Hi Mark, yes I've seen shallower longer bellies on some but not all and will surely consider that. I did measure the depth of the dish with a credit card and pushed various card stock underneath and it's at or less than .008" deep. Is that too much? Great idea on making my own radiused sanding block, thanks a metric ton for the tip. I'll try it on the twin and maybe go back to this one cause I'm about .02" all around and Stacy said in another thread 6mm from the spine and 3mm from the edge iirc.

 

[Brock Cutlery]

Hi Mark, yes I've seen shallower longer bellies on some but not all and will surely consider that. I did measure the depth of the dish with a credit card and pushed various card stock underneath and it's at or less than .008" deep. Is that too much? Great idea on making my own radiused sanding block, thanks a metric ton for the tip. I'll try it on the twin and maybe go back to this one cause I'm about .02" all around and Stacy said in another thread 6mm from the spine and 3mm from the edge iirc.

I wonder if you are getting some give on that sanding block. That doesn't sound deep, but maybe it is right. I never measured mine. My first couple were done on a 14 inch wheel. I've since moved to one of Nathan's 36" radius platens, which is much better.
As far as the border, I've kept spine and edge relatively even, just based on my own research.

Check out this one. This maker is pretty greatly respected. That border appears to be an insane 1mm all around, and soooo close to the tip.
This is what to shoot for, but probably a long time in achieving this level of skill. This is actually done by carefully grinding to the edge then take it to the stone. ...But to keep it even for the length of the blade, that is the skilled execution that is difficult. Keep in mind their stone wheels are much wider than our standard 2 inch belt.

There is so much going on with these blades, needless to say. I would encourage you to study the taper of the shinogi relative to the spine, and also the amount of belly on the blade above.
It is a phenomenal blade of course, but we have to aim high eh?

 

[Stacy E. Apelt - Bladesmith]

I did some math.
If the grinding wheel is 72", and the urasuki is 1" wide, the depth of the urasuki is .004".
On a 48" wheel, it is .005" deep.
on a 36" wheel, it is .007" deep.
On a 16" wheel, it is .015" deep

The normal hollow ground urasuki is on a 48" to 72" wheel.
No need for it to be deep, as all it does is reduce the contact area, and thus reduce cutting friction.