How To Kitchen knife grinds and how to grind them?

[Diego_B]

First off I am aware that this topic has probably already been beaten to death by other people like me however I am still not quite understanding all the types of grinds that one could put on a kitchen knife. It seems to me that one mans convex grind is not what someone else calls a convex grind and I am still getting somewhat confused in this "pool of grind types". So if some of you that are more knowledgeable than me would explain my questions below I would greatly appreciate it. Thank you!

My questions:

1. What is the preferred way to grind 8" chef knives that are 2" tall at the heel and .90-.100 stock thickness? I understand that there is a flat, convex, S-Grind, any more that I am missing? Could someone go into detail on what each of these grinds are and how does one go about preforming each grind and why?

2. What type of grind would you call this? Would you recommend it? If not, why? What would you do different?

3. What is this "sweeping plunge that I hear about? When is it used and why?

4. Out of any grind type that you could pick which would you pick to avoid food sticking to the blade?

5. How do you grind a chef knife with a belt finish?

Happy new year everyone!

 

[HSC ///]

1) flat to convex
Sorry I don’t time to type all the details. You can research all this on the other forum dedicated to kitchen knives.
2) idk, I don’t have time to sit and watch YouTube videos
3) maybe it’s this -Plunge critic I’ve never seen it on any traditional high performing Japanese kitchen knife
4) s grind
5) I would use the appropriate grit progression belts...

You have made a few kitchen knives, I see that from your Instagram. If you are serious about kitchen knives then I suggest you make the investment and purchase some Japanese kitchen knives and study them. Don’t say you are a poor student because you are likely richer than you think. It’s about choices.

Also part-time makers who make YouTube videos aren’t necessarily the best to learn from for making knives.

Serious makers take classes and learn from other accomplished makers

If any of those 1084 chef’s knives are available, consider offering one as a passaround so you can get some feedback from users

 

[Diego_B]

1) flat to convex
Sorry I don’t time to type all the details. You can research all this on the other forum dedicated to kitchen knives.
2) idk, I don’t have time to sit and watch YouTube videos
3) maybe it’s this -Plunge critic I’ve never seen it on any traditional high performing Japanese kitchen knife
4) s grind
5) I would use the appropriate grit progression belts...

You have made a few kitchen knives, I see that from your Instagram. If you are serious about kitchen knives then I suggest you make the investment and purchase some Japanese kitchen knives and study them. Don’t say you are a poor student because you are likely richer than you think. It’s about choices.

Also part-time makers who make YouTube videos aren’t necessarily the best to learn from for making knives.

Serious makers take classes and learn from other accomplished makers

If any of those 1084 chef’s knives are available, consider offering one as a passaround so you can get some feedback from users

A pass around knife sounds like a good idea. I will plan on making a couple for that purpose and see how it goes. Is there a good thread that might have more information about grind types?

 

[Taz]

3/32" Nitro V choil shot. I do a flat grind first and then use a soft platen (hard felt in my case, others use a rotary platen) to get a nice convex to it, making sure get it nice and thin behind the edge. The soft platen has some give to it, so it will give a convex to the surface you are grinding and make it easier to take to a nice belt finish, too.

 

[Justin W]

There is also a Harpoon, or J grind that is well regarded for food release. It is sort of an extreme S grind with the depression close to the edge.

There are tons of options.
FFG
Convex
Hollow (concave)
Flatvex (mostly flat with convex blending near the spine)
S, J, Harpoon
Saber

Distal taper or no
Choil or no
Plunge or no
Guard or no
Rounded, chamfered, or square spine
Western or hidden tang or frame

Build one as your personal tester.

 

[Dominick Maone]

First off I am aware that this topic has probably already been beaten to death by other people like me however I am still not quite understanding all the types of grinds that one could put on a kitchen knife. It seems to me that one mans convex grind is not what someone else calls a convex grind and I am still getting somewhat confused in this "pool of grind types". So if some of you that are more knowledgeable than me would explain my questions below I would greatly appreciate it. Thank you!

My questions:

1. What is the preferred way to grind 8" chef knives that are 2" tall at the heel and .90-.100 stock thickness? I understand that there is a flat, convex, S-Grind, any more that I am missing? Could someone go into detail on what each of these grinds are and how does one go about preforming each grind and why?

2. What type of grind would you call this? Would you recommend it? If not, why? What would you do different?

3. What is this "sweeping plunge that I hear about? When is it used and why?

4. Out of any grind type that you could pick which would you pick to avoid food sticking to the blade?

5. How do you grind a chef knife with a belt finish?

Happy new year everyone!

1. Flat- flat platten. Convex- Slack belt or soft backer on platten. S-grind- wheel on spine side, slack belt or platten closer to edge. I like s-grinds but mostly because I like the way it looks. Concave aka hollow is done with a wheel.
Someone mentioned some other grind types.
2. That is a flat grind with a hidden plunge. I would make 5+ knives in this way (maybe skipping the hand sanding part and just being able to see the plunge). I’ve probably watched that video 30 times.
3. I think that’s a smooth plunge. Like a nice looking one but not sure.
4. I think chevron/hook grind is best. But S-grind is more reasonable to make.
5. Just use belts and don’t hand sand and it will be belt finish.

Like Harbeer suggested, there is a kitchen knife forum that has all your answers, look up kippington on that forum. This forum is 10x better for helping new makers I think. But that forum is better for learning about what people like (or think they like) about kitchen knives.

 

[CallumRD1]

I'd agree with the recommendation to check out https://www.kitchenknifeforums.com. There is a wealth of information about kitchen knife geometry there that this forum can't come close to matching. That forum is focused on users of knives not makers so the perspective is different but the insight and experience some of their members have is extremely valuable. I cringe when I see people here recommending full flat grinds for kitchen knives as they perform so poorly in the kitchen. Flat to convex is probably the most common well performing grind, but my personal favorite for daily use knives is a single sided s-grind for food release when chopping vegetables. My last recommendation is to start thinner than you think. Starting with stock 0.100" thick means you'll have to do a lot of grinding and tapering to get the knife to perform well. For a 210-240mm gyuto (chef's knife) I recommend working closer to 0.084" stock thickness. Your thickness at the edge prior to sharpening should be essentially zero. My knives will usually cut paper easily off the grinder before I take them to the sharpening stones. Just be careful not to leave yourself a hollow in front of the heel making it so part of your edge doesn't meet the cutting board.

 

[Diego_B]

1. Flat- flat platten. Convex- Slack belt or soft backer on platten. S-grind- wheel on spine side, slack belt or platten closer to edge. I like s-grinds but mostly because I like the way it looks. Concave aka hollow is done with a wheel.
Someone mentioned some other grind types.
2. That is a flat grind with a hidden plunge. I would make 5+ knives in this way (maybe skipping the hand sanding part and just being able to see the plunge). I’ve probably watched that video 30 times.
3. I think that’s a smooth plunge. Like a nice looking one but not sure.
4. I think chevron/hook grind is best. But S-grind is more reasonable to make.
5. Just use belts and don’t hand sand and it will be belt finish.

Like Harbeer suggested, there is a kitchen knife forum that has all your answers, look up kippington on that forum. This forum is 10x better for helping new makers I think. But that forum is better for learning about what people like (or think they like) about kitchen knives.

Thank you very much!

 

[Diego_B]

3/32" Nitro V choil shot. I do a flat grind first and then use a soft platen (hard felt in my case, others use a rotary platen) to get a nice convex to it, making sure get it nice and thin behind the edge. The soft platen has some give to it, so it will give a convex to the surface you are grinding and make it easier to take to a nice belt finish, too.

So in doing this, do you grind your flat bevel like normal keeping it even all the way across? How high do you tend to make your flat grind bevel up the knife before deciding to blend it all together?

 

[FredyCro]

That is a good tutorial for a common grind of a chef knife. Other aproach is to grind even across whole length, then taper towards the tip and blend in the grind. Vachon knifes on instagram has awesome grind tutorials, including the convex and diamond (s-grind) grinds.

It will also give you an idea how much you need to taper if you start with a 2.5-3 mm stock (a lot). I like starting with a thicker stock (2.5-3mm) on the 180mm+ chef because I can taper as needed and still have a stronger lower portion of the blade (towards heel).

 

[Taz]

I grind a full flat grind with a little distal taper and the regrind it on the felt platen. I usually go back and forth with the felt and glass platen to get the performance I want in terms of convexity and thickness.

 

[Hubert S.]

I grind a full flat grind with a little distal taper and the regrind it on the felt platen. I usually go back and forth with the felt and glass platen to get the performance I want in terms of convexity and thickness.

That's pretty much what I've been doing. In all honesty, food release with the slight convex is better than FFG, but still not great with certain foods. I am planning to try some S-grinds sometime this year.

Here is a video by butcher_block that helped me a lot when I started.

 

[Michael Black]

That is a good tutorial for a common grind of a chef knife. Other aproach is to grind even across whole length, then taper towards the tip and blend in the grind. Vachon knifes on instagram has awesome grind tutorials, including the convex and diamond (s-grind) grinds.

It will also give you an idea how much you need to taper if you start with a 2.5-3 mm stock (a lot). I like starting with a thicker stock (2.5-3mm) on the 180mm+ chef because I can taper as needed and still have a stronger lower portion of the blade (towards heel).

I second the recommendation for Noah Vachon's IG stories. It's the best overall description of grinding a good convex chef knife that I've seen. Don Nguyen has some good grinding videos on YT as well. Salem Straub has a series of YT videos about how he does an S Grind, and Mareko Maumasi has lots of tips and tricks about it on his IG. Alec Steele explains some of Mareko's advice in one of his chef knife video series he did too.

I highly recommend checking out the kitchen knife forums referenced above, as well as the chef knives subreddit (www.reddit.com/r/chefknives) for all about cutting geometries from the user perspective. Another good resource for knife geometries overall is Larrin Thomas' book Knife Engineering. Don't forget to take into account the steel hardness in conjunction with the geometry.

Personally what I've been doing to improve my chef knives has been to start buying various production knives and see how different types of grinds work in person.

Enjoy the process!

 

[Diego_B]

That is a good tutorial for a common grind of a chef knife. Other aproach is to grind even across whole length, then taper towards the tip and blend in the grind. Vachon knifes on instagram has awesome grind tutorials, including the convex and diamond (s-grind) grinds.

It will also give you an idea how much you need to taper if you start with a 2.5-3 mm stock (a lot). I like starting with a thicker stock (2.5-3mm) on the 180mm+ chef because I can taper as needed and still have a stronger lower portion of the blade (towards heel).

Watched his grind tutorial on Instagram and now I want to try it out!

Is there a specific grit finish that most apply to their blades if doing a belt finish? Would something like this work out? 36, 80, 120 ceramics followed by a A100 and A45 trizact and lastly a 400G cork?

So It looks like how most seem to get a convex grind is by grinding your primary bevel first and then start to distal taper the blade by bringing the grind higher up starting around the middle point of the blade and going to the tip. From here it looks like you true up your bevels and then you can start to blend in the grind add your convex to the blade by rocking it back and fourth between the primary bevel and the blade flats.

I will have to start trying things now and see about letting people demo them. I'll also be sure to check out the kitchen knife forums.

 

[Hubert S.]

Is there a specific grit finish that most apply to their blades if doing a belt finish? Would something like this work out? 36, 80, 120 ceramics followed by a A100 and A45 trizact and lastly a 400G cork?

I like the scratch pattern to go in the long direction and use Scotchbrite belts. The cork belt finish looks a little better in my opinion, but I cannot get a uniform finish in the length-wise direction with it. The Scotchbrite finish also hides scratches from use very well, much more so than the blades I hand sanded. If you start with a coarse Scotchbrite, you can get rid of the scratches from an A45 belt going across the blade.

 

[HSC ///]

From my own use I think food release is less important than how a knife passes thru food. But I’m not the customer and they are the ones ordering and paying

With that said, here’s a recent 11” Gyuto in the hands of someone who knows what they are doing.
You can see food release varies greatly on the type of food that is being cut.

 

[Cushing H.]

Honestly, i agree with HSC. Ive been cooking and using knives for food prep for a while (~45 years), and food release is very seldom an issue - but how the knife slices IS. Also important (over time) is that the knife does not become wedge-like as it is sharpened over the years. A convexed edge fails on the latter. So ... FFG with a nice low TBE is just-fine as far as i am concerned.

 

[HSC ///]

Honestly, i agree with HSC. Ive been cooking and using knives for food prep for a while (~45 years), and food release is very seldom an issue - but how the knife slices IS. Also important (over time) is that the knife does not become wedge-like as it is sharpened over the years. A convexed edge fails on the latter. So ... FFG with a nice low TBE is just-fine as far as i am concerned.

The grind on this one (bevels) and all my knives are convexed

 

[Cushing H.]

The grind on this one (bevels) and all my knives are convexed

But my concern is maintainability over time as the blade is repeatedly sharpened, and the edge walks back into the thicker convexed area, producing a quickly increasing TBE. A FFG will reduce that ongoing increase in TBE.

 

[HSC ///]

But my concern is maintainability over time as the blade is repeatedly sharpened, and the edge walks back into the thicker convexed area, producing a quickly increasing TBE. A FFG will reduce that ongoing increase in TBE.

Understood
Most of my customers are qualified sophisticated users who thin their own knives