Identifying grinds?

[Holztisch]

Hey KKF!

When I started learning about Japanese knives I didn't really pay attention to the grind beforehand at all. This lead to many buys and sells, since some knives cut well, others didn't. I read a lot about grinds up till now but I hope you all can give me some input. I'd love to hear about your favorite grinds or even steel / knife combinations. I also put some pictures of my knives in the attachment. I'm just trying to guess the choils right. Hope you can help me out.

This is my AZAI Echizen Marukatso AS Santoku and I think it's a flat grind?

This is my Mr. ITOU Custom Damascus R2 Gyuto and I think it's a flat grind too?

This is my Sakai Takayuki Homura Premium Kengata Gyuto in B#2. I don't know the grind actually. Is this an S-Grind?

I also got a Takamura R2 Gyuto but I guess it's a very thin flat grind. Thanks all for reading!

 

[ian]

The first two look like convex grinds, the last one is “wide bevel”. You can see the convexity of the first two in the choil shots. The sides of the blades in the choil shots aren’t just straight lines, they curve.

Wide bevel knives can come with different grinds on the wide bevel, which is the half of the blade closest to the edge in your pic. I can’t tell from the pics what the grind is on the wide bevel. Could be convex, flat or concave.

You’ll hardly ever see a truly flat grind on a kitchen knife that’s not a wide bevel, like the first two. It’s common on folders tho.

 

[mmiinngg]

Put a ruler or something truly flat on the blade so you can judge by yourself looking from the spine to the edge. You will see that, even if it looks dead flat, there is usually a little bit of convexity.

 

[Holztisch]

Thanks for the reply and help guys! Why do people like wide bevel knives in the first place? Can't seem to warm up to them.

 

[tostadas]

Thanks for the reply and help guys! Why do people like wide bevel knives in the first place? Can't seem to warm up to them.

Easy to polish when the bevel is flat.
Nice food release due to the change in angle at the bevel.
Ease of maintenance if thinning in the future.

I was previously not a fan of wide bevels, but the more knives I tried, the more I gravitated toward the cutting feel of this kind of grind.

 

[ian]

Yea, ease of maintenance and looks, mostly. Even if the bevel is convex, the geometry of the bevel is regular enough that it's easy to polish. With a totally convex ground blade, you can't make it look good after thinning just using stones unless you refinish the entire blade, which is usually a nightmare since the geometry's not perfect in the upper half of the blade. So wide bevel knives encourage good maintenance better.

 

[Holztisch]

Easy to polish when the bevel is flat.
Nice food release due to the change in angle at the bevel.
Ease of maintenance if thinning in the future.

I was previously not a fan of wide bevels, but the more knives I tried, the more I gravitated toward the cutting feel of this kind of grind.

Those sure are some strong points. But are they as practical for the normal kitchen routine? For instance can they still chop big vegetable onions without wedging? Or julienne carrots?

 

[tostadas]

Those sure are some strong points. But are they as practical for the normal kitchen routine? For instance can they still chop big vegetable onions without wedging? Or julienne carrots?

Practical in what sense?

I feel that wedging depends a lot on the thickness of the knife. The most important thing for me in a knife is going through onions and carrots because I make a lot of soup. For thick carrots, my rough benchmark is if the maximum thickness behind the edge at 5mm/10mm is approx 0.7mm/1.1mm or less, I find that I can get whisper soft cut through without any cracking. In general for medium size onions and smaller, it works fine too. On super big onions, even thinner is better.

 

[ian]

Those sure are some strong points. But are they as practical for the normal kitchen routine? For instance can they still chop big vegetable onions without wedging? Or julienne carrots?

They typically wedge a bit on hard, tall produce. Splitting an onion or an apple in half will not be a wide bevel's forte. Fine precise cuts are good though. They'll be fine for julienning carrots.

 

[Holztisch]

Thanks both of you for the reply. I always struggle because I think I need to find the one knife that can do everything to a good degree. But I guess every knife has it's strongpoints. I just need to buy a longer magnet bar for my wall .

 

[LucasFur]

Really sorry to maybe put a dampen on peoples thoughts.

I'll chime in a little ...
There is a lot of weird information out there.
My understanding is that S-Grinds are hollowing out of the middle of the blade. (this is what i define as S-Grind now) S-Grinds, are they worth it? | Topham Knife Co I also heard S-Grind originated with the shigefusas ... where it was still a "typical Convex grind" done on a belt, but thick enough at the edge for professional use without chipping. Opposite of the Kato Grind, where its very thick at spine and very thin at edge of the blade.

In my experience ... the only knives with Hollow'd S-Grinds are Shiro Kamo/ Old Takeda's ... and Dalman's
Dalman's -- seem to have a convex with the S-grind
Shiro Kamo/Takeda have varying S-Grind with Scandi Grinds.

The truth is there are soo many nuances in Grinds, its pretty hard to to really get a good idea. And 99% of the blades out there are convex grinds ... and will become wide bevels through sharpening. (probably still convex grinds, but wayy less than what comes from factory) Also, its not just the grind that matters, is where the metal is forward/ backward that matters. a perfect convex grind can still be brutal if there is no steel removed from the tip. Look at Kip's grind chats for more info. Check out alot of his posts .. the guy is the grind God. Food Release: Stiction and the Grind
You gotta find the one that he posted drawing what a KATO grind is like.

Your knives posted.....
Having thinned my wifes Itou. I can say ... i have no idea what the grind is. its too inconsistent. the Damascus actually hides a surprising amount of variation in there ... Post thinning, doing what i can ... its a chizel/ Convex with a 1 sided micro-bevel ... and it cuts straight for her being a lefty so we're GOLDEN.

The Marukatso AS seems super thin, its a pure convex grind. Im sure it could perform better with pure thinning behind the edge ... but I would suspect it cuts pretty good.

Takayuki Homura .... Hmm its defiantly not a flat grind. Having handled that knife at a knifewear ... its fit/Finish is amazing ... its very expensive ... its very consistent in both grind and between each blade (which is a hallmark of cost). I dont think you should judge what a flat grind knife is off of it though. its just not that great (IMO) out of the box. It needs a good Ol' thrashing on the stones to actually put a flat chizel grind on it ... and it'll be amazing. ... i've had 2 Sakai Takayuki with the same grinds, both are now stellar performers, but needed that intamacy time on the stones to relief that thickness behind the edge. this knife was produced for the "western" market with what Japanese believe westerners want ... thicker/ durable knives that can be used for everything WITH a high fit and finish ... turns out they got their clients 1/2 right ... but people on this forum probably are looking for something other than this knife ... BUT they have real potential if you put it on the stones and make it what you personally want ... which i would actually recommend with any knife after you make the decision to use it deeply. because of that grind people often dump on BST ... where the values are amazing because your getting a really good knife that needs stone love to be a true shiner.
(And i dont mind saying negative things because Knifewear, and other places selling this knife dont look on KKF ... I always ask, and they never have any idea)

 

[Holztisch]

Thanks for the reply

I will try to thin my Sakai Takamura. Maybe it performs better this way. You are right, it was very expensive. I actually saved up for it, because I thought this is THE final knife for me. Boy was I wrong. Still can't stop the urge, wanting to try different knives..
I actually love the Marukatsu Santoku. I've noticed that there are barely any trades or sells with santokus here. Maybe because it's not a traditional knife form? Can really recommend this one though. Hardness is rly high, at least 65 hrc. Some say it has 67. Keeps an edge well and cuts very nice.

I really have to get the eye for when to thin a knife and where to start. It didn't occur to me at all, that I could or should just thin them. And thanks again for your help

 

[ian]

In my experience ... the only knives with Hollow'd S-Grinds are Shiro Kamo/ Old Takeda's ... and Dalman's
Dalman's -- seem to have a convex with the S-grind
Shiro Kamo/Takeda have varying S-Grind with Scandi Grinds.

Catcheside has a more subtle forged in S than Takeda (I think?) but it’s still there. Kamon does extreme S grinds like Dalman. I’m sure there are many others...

Also, to the OP, the goal of thinning is not necessarily to make the grind flat near the edge, it’s to make it thinner (and potentially flatter, but not flat). Completely flat grinds, or even flat grinds on wide bevels, are to be avoided in the kitchen.

 

[DavidPF]

Correct me if I'm wrong, but I think an S-curve has that name because the face of the blade is convex near the edge, then concave further up.

 

[DavidPF]

Completely flat grinds, or even flat grinds on wide bevels, are to be avoided in the kitchen.

Would this mean that taking down an inconsistent bevel until it's flat might actually be worse than doing nothing?

 

[mmiinngg]

Those sure are some strong points. But are they as practical for the normal kitchen routine? For instance can they still chop big vegetable onions without wedging? Or julienne carrots?

I don't use them the same way (wide bevels vs laser) (warning, for some users I might be doing a shortcut between laser and flat grind, but if I look at my set up, the ones that look the more flat are my lasers.))

With a wide bevel I tend to use the entire length of the blade (preferably 240mm) with a slicing or pushing motion, especially for large veggies eg celery root. The tip is also very very useful as it is the thinnest part of the knife (wide bevels usually come with a pronounced distal taper), which can easily ghost through onions, carrots or apples without wedging, if your technique is quite good.

With a laser, you can cut almost anything by pressing downward.

My opinion is that the laser will look more user-friendly and give you that satisfying feeling of cutting through almost anything like it's hot butter.
But I find the wide bevels a lot more fun to use, due to its shape / geometry, once your technique is good enough to benefit from all the characteristics of the blade (tip, heel, length, height and weight)

 

[mmiinngg]

Catcheside has a more subtle forged in S than Takeda (I think?) but it’s still there. Kamon does extreme S grinds like Dalman. I’m sure there are many others...

Takeda S grind is garbage in my opinion. The result is you get a super thin blade wedging like a monster workhorse wide bevel.
Had to thin the hell out of it to perform decently.
Can't compare to the others you mentioned yet. Waiting for the dalman massdrop to try another s grind.

 

[JaVa]

There are so many different variations with every style of grind that it's impossible to categorize any style as just one thing. There are wide bevels and there are wide bevels.

Here is the original design of a Yu Kurosaki Shizuku wide bevel.
https://www.cleancut.eu/butik/knife...urosaki-r2/kockkniv2015-01-29-11-56-53-detail... here is the current version of the same Shizuku wide bevel knife, but with the new updated and upgraded design.
https://cuttingedgeknives.co.uk/collections/yu-kurosaki/products/yu-kurosaki-shizuku-gyuto-240mmSee how much higher that wide bevel continues and how much higher that shoulder is? The first might wedge on tall hard products (though it's been reported to be a great cutter). But the new one certainly won't and will feel like a laser. That difference means that the thinness behind the edge continues higher and the shoulder is smoother, but also it will change the balance point as there is less metal and weight.

This is a S.Tanaka B2 KU with wide bevel. It's his old style wide bevel design and it's actually convex grind. It's not the thinnest behind the edge, but still he knows how to make that edge geometry work and it's a great cutter with nice food release. The convex-ness starts to turn away from product that's been cut to push it away from the blade.
https://cuttingedgeknives.co.uk/collections/yu-kurosaki/products/yu-kurosaki-shizuku-gyuto-240mmThis the S. Tanaka Nashiji and it's his newer design.
https://www.knivesandstones.com.au/...aka-blue-2-nashiji-gyuto-240mm-stainless-cladYou can see that grind rides higher, though the difference isn't as dramatic as with the Kurosaki knives. But the wide bevel on the nashiji is actually slightly concave to enhance the thinness behind the edge compared the KU. That thinness continues pretty high and the shoulder is more pronounced. The cutting performance is very effortless. The concave grind leaves an air pocket between the product and the blade and that sharper shoulder starts to push the product of the blade. I've owned the KU and have two of the nashijis.

That's just four different executions of a wide bevel grind and then there is all the variations in between.
I'm not the biggest fan of a true flat grind wide bevel, but when they are thin enough where it counts and also the well made convex and concave grinds are great IMO.

Also the thinner the grind is the less important and/or possible the convex grind becomes.

 

[toddnmd]

Takeda S grind is garbage in my opinion. The result is you get a super thin blade wedging like a monster workhorse wide bevel.

I’d say they vary. Some wedge, some are quite thin with good food release.

 

[RDalman]

Dalman...

I generally do concave/concave, and I don’t consider my knives to have crazy food release, rather aim for something "balanced" in regards to ease of cut/release. That topham article doesn't describe what I do imo. Edit: I mean generelly, alot is correct but alot also is assumptions and definitions not entirely so.
Edit again; pics

 

[mmiinngg]

@RDalman, isn't concave / concave an s grind?
If not, then what the heck is a s grind ?

 

[Holztisch]

I generally do concave/concave, and I don’t consider my knives to have crazy food release, rather aim for something "balanced" in regards to ease of cut/release. That topham article doesn't describe what I do imo. Edit: I mean generelly, alot is correct but alot also is assumptions and definitions not entirely so.
Edit again; pics

Wow that's a crazy grind. How does it cut?

 

[RDalman]

@RDalman, isn't concave / concave an s grind?
If not, then what the heck is a s grind ?

That grind I do is referred to generally as s-grind yes.

Wow that's a crazy grind. How does it cut?

Cuts ok, I hope

 

[Luftmensch]

My understanding is that an S-grind is a concave blade face followed by a convex primary bevel (concave/convex). Dip and bump. Shigefusa does make a S-grind. The concave (hollow) on the blade face is very subtle. You have to hold a ruler against the knife to see it. Takeda is much more exaggerated...

If you want to hårklyveri (nitpick/split hairs/be an@lly retentive)... I wouldnt call @RDalman's grind an S-grind... I would call it a 'double hollow' or 'double concave'. Dip and dip. I believe there was a period of time where @RDalman even made a 'triple hollow'!! That is pretty cool!

Forget the blade face and look at the primary bevel. To me, an S-grind implies a convex bevel whereas @RDalman's are hollow/concave.

But if you are more relaxed... eh... 'S-grind' captures the idea of a 'fuller' followed by some bevel

 

[RDalman]

'triple hollow'!!

I still kindof do sometimes, sometimes upper face (by spine) is more like two sections. For me the blade faces are like three sections, and I use wheel to grind/finish on

 

[Luftmensch]

For others; it is a cool effect! Checkout an example in this post.

I still kindof do sometimes, sometimes upper face (by spine) is more like two sections. For me the blade faces are like three sections, and I use wheel to grind/finish on

Gotta try one, one day! I bet it would reduce the weight by a fair margin while keeping a similar stiffness. Not to mention allowing for a razor edge!

 

[Holztisch]

For others; it is a cool effect! Checkout an example in this post.



Gotta try one, one day! I bet it would reduce the weight by a fair margin while keeping a similar stiffness. Not to mention allowing for a razor edge!

How do you even sharpen such a grind?looks totally cool!

 

[ian]

How do you even sharpen such a grind?looks totally cool!

You sharpen it just like any other knife. You create it with a grinding wheel, or a belt that goes around a wheel.

 

[Holztisch]

You sharpen it just like any other knife. You create it with a grinding wheel, or a belt that goes around a wheel.

Ah okay, I was thinking about Japanese whetstones

 

[DavidPF]

Ah okay, I was thinking about Japanese whetstones

That would take a lot less time than fingernails, but a lot more time than a grinder.