# Food Release: Stiction and the Grind



## Kippington

I don't know about you guys but I'm fascinated by food release. It's surprising how little information is out there on the subject, despite it being a hugely desirable property in a knife - especially among those of us who work in the food industry.







With a craving to learn more, I recently attempted to make my first knife designed specifically to tackle this topic. The knife was a partial success, the food release is amazing but the design was too demanding on the steel. Internal stresses from the differential HT plus crazy thin cross-sections towards the tapering tip caused the blade to warp out of shape and subsequently it broke on the attempt to straighten it out again... so now I have a nice non-stick nakiri! :lol2:






I'm pretty sure I can take this experience and redo the knife with some improvements to stop this from happening again, so over the next few weeks I will re-design and create a new one while posting updates to this thread. I hope to go into some of the details of how it works, the problems this kind of grind creates, a few solutions and a bit of other fluff. Hopefully there's a bit of interest out there! :biggrin:

[video=youtube;CodmXr9MUks]https://www.youtube.com/watch?v=CodmXr9MUks[/video]


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## Barmoley

Sounds very interesting Kip. Thank you for sharing and please update with progress.


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## Nemo

Really intersted to see how it goes. Also interested in your thoughts on which grind features are best dor food release.


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## chinacats

Nice and I too am a big fan of good release. While I know nothing about design or knife making I'm curious why you're taking this approach vs a simple convex grind which tend to be my favorite?


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## HRC_64

Kip, that profile looks like a trad j-knife with the bevel on the 'wrong' side. 
cool project and I'm interested to see how it plays out...


Btw, what is the cross-sectional minimum?


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## milkbaby

I'm assuming that you did the entire grind after HT? If not, that's worth a try although the stresses in the steel can still manifest in warp during post-HT grinding. I'm pretty sure you already knew that tho...

Is it carbon steel? I don't like to crank on the blade while cold to straighten. I always clamp with counterbend and heat to tempering temps again, check straightness after an hour or two, and repeat until straightened. Perhaps best 10-25 degrees F below the original target so as to lose the least amount of hardness as I've read you can lose a teeny bit (maybe on the order of HRc 0.5 to 1 point) repeated extended tempering.


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## panda

this is cool AF, keep us posted when you do food-no-sticky knife 2.0


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## RDalman

chinacats said:


> Nice and I too am a big fan of good release. While I know nothing about design or knife making I'm curious why you're taking this approach vs a simple convex grind which tend to be my favorite?



Can only reply for myself, but consistency. Convex involves slack belt grinding/finishing, or "wobbling" grinding and is very difficult to pull off consistently knife to knife. The "sweet spot" is very small (making wise).


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## chinacats

RDalman said:


> Can only reply for myself, but consistency. Convex involves slack belt grinding/finishing, or "wobbling" grinding and is very difficult to pull off consistently knife to knife. The "sweet spot" is very small (making wise).



Thanks for the explanation Robin...it's funny because this grind looks so much more difficult to someonewho doesn't know.


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## Kippington

panda said:


> this is cool AF, keep us posted when you do food-no-sticky knife 2.0



Will do!



milkbaby said:


> I'm assuming that you did the entire grind after HT?



Yep, the knife was completely straight and tapered before I started on the hollow, much like this:






But while grinding out the middle, the steel got much thinner then I had anticipated. To answer HRC_64, it broke with a 0.5mm center cross-section






In a nutshell, the water quench caused the sides of the blade to expand more than the center, resulting in compression on both the left and right with a tensile stress in the middle. Grinding away much of the right side caused the left side to expand throwing everything out of whack. There's a huge amount of science involved in this, but I'll leave it there for now.. suffice it to say there's a whole lot of static pushing and pulling going on inside the knife!


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## Kippington

Nemo said:


> ...which grind features are best for food release...





chinacats said:


> ...I'm curious why you're taking this approach vs a simple convex...



Ah, now _*this*_ is the science I want to get into! :lol2:

I'm sure we've all tried those laughable knives with gratons/scallops along the side after being told, "They help the air get between the food and the blade", only to find they did absolutely nothing to aid food release:




But then Glestain comes out with mega gratons which apparently work quite well (I've never had the chance to try one myself):




And later we get the el'cheapo Aero Knife, with gratons that go through the entire blade.






Now while the Aero Knife itself is terrible, they were onto something when they advertised it as having less surface area to stick to food. In fact many of us have intuitively worked this out already, while slicing something like a tomato and seeing that food falls off much easier at the tip of the knife rather than at the heel. This is because at the tip of the knife you get:

*Less blade height &#8594; Less surface area &#8594; Less food-to-blade contact &#8594; Improved food release*

And that's when I realized what this bump on the blade needs to do: Emulate the 'faux top' or spine of a knife that has very little height.






And the theory seems to check out on the test knife. As you can see in the video, tomatoes get pushed off to the side, and I was surprised to see the same while dicing the onion! It's bizarre to see most of it sitting there at the end as if it hadn't been touched. It's worth noting that the first few cuts on the onion are below the faux height of the knife, and so a couple of pieces hold on at the beginning but then get pushed up and off the bump by the following cuts. After that, nothing seems to be sticking.

Armed with this knowledge, its time to design a new knife around this 'bump'!


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## Nemo

Makes sense. My Tristone with a double convex grind has really excellent food release for such a thin knife. I guess that the convex on the top half of the blade effectively reduces the height of the blade that the food sees.

This would also explain the S-grind's effectiveness, I guess.


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## HRC_64

This is interesting...but

Personally, I try to draw-cut something that presents a major stiction risk. 

Theres probaly some logic why it works, empirically (or anecdotally),
but it does seem food sticks alot less this way (grind notwithstanding).

so overall this is a fascinating topic to learn about.

good thread.


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## daveb

Somewhat related - Pens Tiger did a evaluation of sticktion on some popular brands a couple years ago. Someone with more google-fu than I would have to link it.


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## Kippington

Is a draw-cut the same as a pull-cut? Because if so you would finish the cut towards the tip of your knife, aiding in food release for the reasons I've hopefully explained in my last post.

Nemo, I've never seen a Tristone before. Can you post a choil shot?


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## Pensacola Tiger

daveb said:


> Somewhat related - Pens Tiger did a evaluation of sticktion on some popular brands a couple years ago. Someone with more google-fu than I would have to link it.



Totally unscientific, and I don't have half of the knives I "tested", but here's the link:

https://www.youtube.com/channel/UCc...?sort=dd&view_as=subscriber&view=0&shelf_id=0

"Many potatoes gave their all for these videos."


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## Kippington

Ah yes, thank you Dave and PT. Those videos will play an important roll later on because, even though I'm trying to reduce the contact between food and the blade, the area where they _do_ touch will still need to be worked out. This happens closer to the end of making the knife.
PT, I think your tests are hiding a few secrets we can uncover! :biggrin:


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## jessf

sharpens like a single bevel? That bump will disappear as you sharpen, no?


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## Nemo

Kippington said:


> Nemo, I've never seen a Tristone before. Can you post a choil shot?



I will but it may not help. Chadd only ground double convex on the distal 2/3 because he was worried about upsetting the knife's balance if he did it the whole length of the blade.


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## merlijny2k

Interesting read! You make it sound like using an air-hardening steel might be more forgiving and allow for the original profile to work. Another approach I have seen a smith take is to heat the blade in the forge to quite somewhat above quenching temp, than letting it air-cool for a while. That way at the start of the quench the temp is no longer even as the outside of the steel has cooled much more to the air than the inside. That should even out the shrinkage levels to a degree.


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## JohnnyChance

Essentially a highly exaggerated and focused on a single side Shige or Takeda grind.


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## Drosophil

Now that's an S-grind! I'm going to ask the obvious: how's the wedging? Can it be made tolerable or is it a one trick pony? Not that I'm complaining, it's a hell of a trick.


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## milkbaby

I'm gong to make an educated guess that the deep concave grind caused warping left to right lengthwise and tacoing spine to edge to the right hand side. Maybe you could lessen the degree of warp to correct by going with a more shallow concave section and/or lower height fuller which removes less metal. Did you grind the left side full height convex or is the curvature 100% from warping only?

There are some custom Xerxes with fuller which was intended for aiding food release. Didn't know if you've seen them:






Also IIRC, Robin Dalman does his S-grind wth a slight hollow grind for the lower cutting bevel (please correct me if wrong, Robin). This would serve to drive the cut food away from the blade as the angle of approach to the shoulder increases towards the top of the hollow grind bevel.

Interested in hearing more of your thoughts and seeing the next iterations!


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## HRC_64

Intersting point above. 
curious how this works out.

Question about that xerxes....

What are peoples thoughts about
taking mass out of the distal spine
like that?

pros/cons?


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## zetieum

Kippington said:


> I don't know about you guys but I'm fascinated by food release. It's surprising how little information is out there on the subject, despite it being a hugely desirable property in a knife - especially among those of us who work in the food industry.
> 
> 
> 
> With a craving to learn more, I recently attempted to make my first knife designed specifically to tackle this topic. The knife was a partial success, the food release is amazing but the design was too demanding on the steel. Internal stresses from the differential HT plus crazy thin cross-sections towards the tapering tip caused the blade to warp out of shape and subsequently it broke on the attempt to straighten it out again... so now I have a nice non-stick nakiri! :lol2:
> 
> 
> 
> 
> 
> 
> I'm pretty sure I can take this experience and redo the knife with some improvements to stop this from happening again, so over the next few weeks I will re-design and create a new one while posting updates to this thread. I hope to go into some of the details of how it works, the problems this kind of grind creates, a few solutions and a bit of other fluff. Hopefully there's a bit of interest out there! :biggrin:



I would indeed expect good FR from this geometry, however this geometry may be poor in hard food. Carrots etc. Especially if one wants to cut somthing else than fine slices: I would expect it not to cut straight. 
Have you tried a big carott/potatoe?


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## LifeByA1000Cuts

I guess no thickness profile trick will ever keep brunoised garlic or chiffonaded hard leaves from having to be scraped off the blade with a dough scraper, then off the dough scraper with the knife, repeat 2-4 times?


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## Kippington

To answer a few questions above:

Yes, it does wedge a bit and steers to the left a little. However, now that I've learned how the bump work, I reckon I can shrink the size of it without compromising its ability to release food.
Basically the plan is to create a knife with better food release than a convex/flat grind knife of the same thickness. If I can't do that, all the theory I've gone through would be incorrect and all that effort would be for naught.

Milkbaby you are correct about the 'tacoing'. The edge on the left side was convexed on the grinder though.
It's hard to see it, but I have done the slight hollow grind for the lower cutting bevel. Works a treat for food release and has the added benefit of making the knife thinner behind the edge.

Changing the depth of the concave section and/or lowering the height of the fuller makes a huge difference to food release.
I'll go into more detail later, I g2g to work.


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## jessf

My first knife had a granton edge and after 10 years of use i had sharpened it down to the scallops. Mind you i didnt thin anything as i went as i didnt know thinning was a thing. So, as single and double beveled knives can be thinned, what would you suggest as a long term strategy for maintaining a knife with this profile?


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## Kippington

The easiest thing to do would be to sharpen it as a normal double bevel. When it needs thinning you'd have to remove some of the bump a bit at a time, which would send it further up the face of the blade until eventually it would disappear completely. It would become a *very* thin knife at this point...

As I mentioned above, I'm working on designing a knife with a smaller bump that hopefully retains its non-stick properties. I believe a bump designed like this would work better the original, without having to grind out as much of the blade middle:






And if it's efficiency increases, I can change the green area to a thinner cross-section to help reduce wedging.

The problem is... I don't think I can make that sharp indent look nice in reality. I'm currently waiting on a much smaller contact wheel to arrive in the mail - half the size of the original one. I will try to use it to get a similar effect.

Before I start, what do you guys think? Is there something I've missed?


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## Kippington

Welp, I've started on the knife. I've gone through the standard steps of forging, heat-treating and the grinding of the taper. Now for grinding the 'bump'... or in this case, a 'step'.

This style of knife is a first for me, so I jumped straight in with a willingness to fail. As of yet it's turning out really well and surprisingly easy - no problems have come up either. Last time the knife had already warped out of shape by this stage.






The step gets smaller as it heads towards the tip of the knife. This is because of the taper. If the step had been ground the same depth all the way, it would've gone though the thickness of the tip. 






In these pictures it weighs 192 grams and the edge length is roughly 230mm. I'll start grinding the bevels and see what happens. Looking forward to testing this baby out on some food!


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## Nemo

Looks cool Kip. Really interested to see how it goes.


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## Kippington

Nemo said:


> Looks cool Kip. Really interested to see how it goes.



Thanks Nemo!

It's getting late so I'd better stop before I piss off the neighbors.
The knife is coming along nicely. I should be able to finish it tomorrow and get some testing done.


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## Dave Martell

Now that's something new! This is going to be interesting - following.


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## labor of love

Fish hook grind haha. Cant wait to hear how it performs.


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## cheflivengood

That looks like a winner, dibs first on passaround


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## panda

Catch some fishies &#128033;&#128033;&#129416;&#129416;&#128032;&#128031;


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## chinacats

Interesting concept but can't see how it would hold up to a few thinning sessions?


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## LifeByA1000Cuts

Food catch-and-release 

Wonder how it will deal with fine dicing (danger of throwing a confetti party by erratically pulling slices out of the stack)?

Also, do I get it right that the hook is on the underside when cutting right handed parallel to board? Hope it is, otherwise gravity is going to really heckle you ...


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## Kippington

Chinacats, all the knives that have been pictured in this thread would have similar long-term issues with thinning. This one would do pretty well, all things considered. There's enough meat in there to have a full thickness knife, even after the 'step' has been ground away.



LifeByA1000Cuts said:


> Also, do I get it right that the hook is on the underside when cutting right handed parallel to board?



Underside of what exactly? I'm not following.


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## Kippington

This knife is growing on me. :biggrin:
I've added an old handle that was lying around and sharpened the edge. The knife looks pretty good considering it has no polish whatsoever (straight off the 60 grit belts).






It's a tad clunky in the hand - a little heavy for me at 192g overall. People that like heavier knives would love this thing. It feels *solid*.
I tested it on a cucumber and it seems to work pretty well. More testing to come soon.

[video=youtube;UO3oOFJ8Fjo]https://www.youtube.com/watch?v=UO3oOFJ8Fjo[/video]

I consider this a success as a proof-of-concept, but as a knife I think it could be done better. I will think it over for a while, spend a little more time cutting with this one, then start on an improved thinner version.


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## Nemo

Kippington said:


> Underside of what exactly? I'm not following.



I think he means that when doing horizontal cuts (e.g.: when dicing onions), the tip of the hook will be facing the board.


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## labor of love

This video is unavailable....


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## labor of love

Nemo said:


> I think he means that when doing horizontal cuts (e.g.: when dicing onions), the tip of the hook will be facing the board.



Even if thats the case the area behind the edge shouldnt be in contact with the board.


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## Kippington

labor of love said:


> This video is unavailable....



Thanks, fixed it. I accidentally had the video set to 'private' instead of 'unlisted'.

[video=youtube;UO3oOFJ8Fjo]https://www.youtube.com/watch?v=UO3oOFJ8Fjo[/video]



Nemo said:


> I think he means that when doing horizontal cuts (e.g.: when dicing onions), the tip of the hook will be facing the board.



Ah that makes sense. The answer is yes, it's a right-handed knife with the hook on the right-face, the left face being standard convex. I can make left handed versions easily enough - it's not _too_ hard to grind the basics of this knife. The real trouble starts when I try to narrow each individual component to its upper performance limit.


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## Nemo

That food release looks great.


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## labor of love

The food release is really impressive IMO. The question that remains is how much pure cutting ability(lazering through food) is sacrificed to get that sort of food release.


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## HRC_64

Ok, needs the carrot video next


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## HRC_64

labor of love said:


> The food release is really impressive IMO. The question that remains is how much pure cutting ability(lazering through food) is sacrificed to get that sort of food release.



make these kinds of designs incrementally thinner 
vs. to see if failure rates get in the way


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## bkultra

Kippington looks like you could use a larger board :biggrin:


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## LifeByA1000Cuts

@Nemo my point was, if the hook was facing up, it could become quite an annoying task to get the knife unstuck because gravity would push whatever is laying on top of it against the hook, so lifting the knife won't help.


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## Nemo

LifeByA1000Cuts said:


> @Nemo my point was, if the hook was facing up, it could become quite an annoying task to get the knife unstuck because gravity would push whatever is laying on top of it against the hook, so lifting the knife won't help.


Yeah, this is an interesting point. Coould it happen with the hook facing down as well? Maybe depends on the ingredient being cut and which cuts have already been made in it. Will be fascinating to see how it works in practice.


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## Danzo

Whoa that food release is insane!


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## Kippington

Danzo said:


> Whoa that food release is insane!



Thanks guys!

As some of you have noticed, the knife was quite thick behind the edge and - as to be expected - didn't perform so well against harder foods.
So now I'm sure that the general idea works, it's time to optimize the grind. I've added depth to the shinogi-step and turned the right-side primary bevel into more of a concave grind. Basically I've taken a lot of the unnecessary steel out of the places where it wasn't needed. It has lost 36g, and is now 166g with the handle. This amount of grinding has caused the knife to warp slightly off center, however it's not enough of a problem for me to bother doing anything about fixing it (most people wouldn't even notice it, and it's easier to fix closer to the end of the process).

It's ready for more testing, I'm off to the shops to buy some harder foods to cut up. Ugh, I've eaten so much potato and carrot in the last few days... the things I do for research and development!


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## inferno

hey kip what radius are u using for that transition?

or are you using the side of the belt to create it??

I'm just an amateur in making sh1t


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## Kippington

I'm using the side of the belt.
I was using a radius wheel on the first attempt (first picture on the first page), but I feel I can get better results using this 'belt edge' technique.

I am also just an amateur in making sh1t. But I guess I've spent many years waving knives around in commercial kitchens, so that kinda helps...


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## inferno

how would you yourself rate this grind? is it worth it or is a novelty only? I think its very forward thinking, but I dont know if its better than regular so to speak.


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## inferno

Kippington said:


> I
> waving knives around in commercial kitchens, so that kinda helps...


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## inferno

looks pretty bad ass to me. you should commercialize this and make money on it. licence it. imo.


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## inferno

licence it to tojiro or masamoto, say its about 3500% better than regular grind for release. they will buy that.
kipground...


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## labor of love

I really am having a hard time imagining how a knife like that performs. Perhaps make this grind as thin as you can in the future (or use thinner stock) as food release has been the bane of existence for lasers?


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## inferno

labor of love said:


> I really am having a hard time imagining how a knife like that performs. Perhaps make this grind as thin as you can in the future as food release has been the bane of existence for lasers?




what do you mean? itdb kinda obvious how it works. its a scandigrid up to a point, then its not. for stiction/suction

this is revolutionary.


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## labor of love

Yes. I understand the function of the grind. Im curious about what sort of blade thickness would utilize the benefits of this grind the most. Another variable would be how high to make the fish hook bevel, it already seems to be higher than takeda so thats a huge plus.


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## inferno

I'm guessing 3mm thickness woud do. or ever 2,5mm?? kip?

[video=youtube;iasPQmSGWEk]https://www.youtube.com/watch?v=iasPQmSGWEk[/video]


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## inferno

I'm guessintg the whole shebang is that you do it at all


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## Kippington

After substantial thinning, the knife now has very good food separation. Cutting a potato in half is very smooth and quiet, but the overall food release has been compromised a small amount. Food is now able to touch an area of the knife (above the hook) that it previously couldn't get to, enabling it to hold on.
I'm going to spend a little more time tweaking this one to see what I can get out of it. I'm already planning the next one because I believe there's a bit more unlocked potential to gain from this style, considering how well this initial prototype has done.

[video=youtube;caTSvkYqRdc]https://www.youtube.com/watch?v=caTSvkYqRdc[/video]



inferno said:


> I'm guessing 3mm thickness would do. or ever 2,5mm?? kip?



This knife is tapered. The spine is 3.2mm thick at the heel (in the choil-shot picture) and 1mm thick, 20mm away from the tip. This knife covers both of the thicknesses you mentioned.



labor of love said:


> Another variable would be how high to make the fish hook bevel, it already seems to be higher than takeda so thats a huge plus.



Yeah the height of the step has a huge effect on the efficiency of food release. The lower I make it, the better the release while also decreasing its ease of thinning.
You can hopefully see it in this diagram:







Left: Full height circular cut, small contact surface area (in red). Food not likely to stick.
Middle: Half-circle cut, over 50% contact surface area. Food likely to stick.
Right: Lowered step height, half-circle cut. Less than 50% contact surface area. Improved food release over the previous example.

Well this is how I see it working anyway.
Oh yeah, I can also use this diagram to explain that - in this latest video - the full-circle cut is currently touching the knife at the top of the circle. So you can imagine a red area at the top of the circle, helping to hold the food to the knife. This wasn't the case in 'Round 2', but it changed after I thinned the primary bevel. I will try and fix this tomorrow.

------------------

I had gnocchi and mashed potato for dinner tonight. More potatoes to come!


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## Salty dog

LifeByA1000Cuts said:


> Food catch-and-release
> 
> Wonder how it will deal with fine dicing (danger of throwing a confetti party by erratically pulling slices out of the stack)?
> 
> Also, do I get it right that the hook is on the underside when cutting right handed parallel to board? Hope it is, otherwise gravity is going to really heckle you ...



I wonder about the onion thing as well.


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## LifeByA1000Cuts

@Kippington I like how the occasional pulled up slice of cuke is at least thrown well clear of the cutting zone


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## Jville

This is very interesting grind concept you are developing. The food release was extremely impressive in the beginning. You can see it drops off in the last video, but still pretty good. I hope you perfect it!


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## milkbaby

Kippington said:


> Yeah the height of the step has a huge effect on the efficiency of food release. The lower I make it, the better the release while also decreasing its ease of thinning.
> You can hopefully see it in this diagram:
> 
> 
> 
> 
> 
> 
> Left: Full height circular cut, small contact surface area (in red). Food not likely to stick.
> Middle: Half-circle cut, over 50% contact surface area. Food likely to stick.
> Right: Lowered step height, half-circle cut. Less than 50% contact surface area. Improved food release over the previous example.
> 
> Well this is how I see it working anyway.
> Oh yeah, I can also use this diagram to explain that - in this latest video - the full-circle cut is currently touching the knife at the top of the circle. So you can imagine a red area at the top of the circle, helping to hold the food to the knife. This wasn't the case in 'Round 2', but it changed after I thinned the primary bevel. I will try and fix this tomorrow.



The right cartoon is basically similar to the Takeda forged geometry except his are both sides of the blade. You have more metal to play with by only doing one side. I think that's why some people have issues with the lower height Takeda grinds because the bevel has to have enough meat on both sides so there's metal in the center to support the blade. With the one sided hollow, you could actually experiment with the hollow crossing the "centerplane" of the blade (the imaginary plane thru the center of the blade from the center of the spine to the cutting edge). That will also give you more room to play on the best geometry for the hollow, since you said in some cases food touched at the top of the cut portion.

I wonder how much this type of geometry would affect different techniques and foods. What happens if you rock the knife over certain foods? What about slicing and pull cuts (maybe not as important as the knife gets thinner at the tip?).


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## Kippington

milkbaby said:


> With the one sided hollow, you could actually experiment with the hollow crossing the "centerplane" of the blade (the imaginary plane thru the center of the blade from the center of the spine to the cutting edge). That will also give you more room to play on the best geometry for the hollow, since you said in some cases food touched at the top of the cut portion.



I've actually lowered the step/hook to more closely emulate the right picture, so my knife is now a tad closer to the Takeda grind. The hollow doesn't appear to go through the "centerplane" of the blade at the choil picture, but I'm pretty sure it's happening further up the blade due to the taper giving the hollow less space to go. There's probably a way to find out with calipers, but I haven't bothered trying to work out a way to do it.

The reason why the top part of the food touches (in some cases) is two fold. The angle of the primary bevel (below the shinogi step) doesn't angle out enough - hence the food goes closer to straight up, rather than getting pushed out. As I can't undo grinding metal away, it's kinda too late for me to change the angle on this knife. I'll do it differently on the next version.

Secondly, a specific area above the step/hook was curving back out too fast. This old picture helps explain what I'm talking about: the point on the the red curvy line to which the top red arrow points to is where the food was touching. I've since shaved a little bit of metal off this location (it didn't take much) and it has definitely helped with food release.






This prototype is basically finished - I can't remove any metal that would drastically improve performance. I've started on the next one already, forging and heat-treating the blank today. I will finish the current version and post another video soon.


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## Kippington

I shot a quick video while making a salad for dinner. I gotta say, this knife has turned out really well. I'm now completely convinced that this grind has better food release than a convex-grind knife of the same thickness. It took a bit of work to get it right though.

There's a diced onion in there for those who wanted to see it - unless you only wanted to see pieces getting thrown out of the stack! :biggrin:

[video=youtube;ytjDtgbGdn0]https://www.youtube.com/watch?v=ytjDtgbGdn0[/video]


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## Nemo

Looking great.

BTW, what did you dress the sald with?


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## Kippington

Plain old balsamic vinaigrette. I love the simple salads!


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## bkultra

Peel and soak some starchy potatoes in water over night in the fridge and film the results. Jump right to the good stuff


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## Jville

Food release looks impressive! Not an easy task leaving an onion standing like that.


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## HRC_64

Great thread....looks good... and now I want some salad, too


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## Ragustoriches

Really cool thread. That is a wild looking grind, glad to hear that it was a success


----------



## Kippington

Thanks Jville, HRC_64 and Ragustoriches!

Quick update:
I've recently sold this knife to ashy2classy. I've tidied it up a bit, made a dedicated handle for it etc...






He preferred the choil to lean forward towards the tip, rather than curving back, so I changed it slightly:






One thing I've realized; As of yet I've never done a straight-up comparison with another knife. I have access to a factory grind *Masamoto KS 250mm* (shout-out to Marek07 for lending it to me), and I've recorded a quick video with them both in action with the hope it gives a better demonstration of just how much of a difference the 'hook' can make:






[video=youtube;0HGHpgg5HBs]https://www.youtube.com/watch?v=0HGHpgg5HBs[/video]

I gotta admit, when I go back to re-watch the video it looks like I'm using different techniques on each knife to encourage food to stick to the KS... I promise that's not the case at all. What's really happening is the food sticking to the KS changes the balance of the long and light knife with every cut. It throws the center of mass far forward making it harder to control and keep consistent rhythm, slowing me down (that's part of the appeal of the heavier workhorses, it's easier to ignore the changing weight of a heavier knife if food sticks to it). I also hate it when food falls _backwards _into the path of the knife again, and gets randomly re-cut. I try to stop it from happening with the KS and it slows me right down.
When none of this is a problem I can really get into the groove and, instead of slowing down, I begin to speed up.

I love using this hook grind! It's a lot of fun to use and I should really should look into copying/repeating the results. It took many hours of back and forth testing between the grinder and the chopping board to get it to this stage. It's taught me a _huge_ amount about grinds in the process and there are probably a few people out there that wouldn't mind owning a knife like this for themselves.

I should also mention, when I said this earlier (in a different thread):



Kippington said:


> ...my next project is a medium weight knife with the food release of a workhorse and the separation of a 'laser'...



Some people have referred to this, believing I've been working on another project, but in fact I was talking about the development of the knife in this thread. This grind is enough work as it is haha!


----------



## Marek07

OK - I'm sold on the Kippington Hook! (® - patent pending) 

Wanna trade? :wink:


----------



## Kippington

You gotta ask ashy2classy! :laugh:


----------



## Jville

Are you going to make more of these. It looks like it's performing fantastically. Sign me up.


----------



## ashy2classy

Thanks, Kipp - can't wait!


----------



## panda

all i want to know is, when is workpony happening??


----------



## Marek07

Kippington said:


> You gotta ask ashy2classy! :laugh:


I was thinking of the Masamoto for a future Kippington type of trade.


----------



## labor of love

Welcome to the club ashy. If youre excited now, just wait until you sharpen it!


----------



## Kippington

Jville said:


> Are you going to make more of these. It looks like it's performing fantastically. Sign me up.



I agree, I'd love to make more after seeing how well it works in action.
Unfortunately I'm moving house in the next week or two as my lease is soon finished. My knife making - which normally happens in the garage - has to go on indefinite hold. I hope to find a new place where I can keep making a huge, noisy, dusty mess in the future.



panda said:


> all i want to know is, when is workpony happening??



YOU GOTTA EARN IT!!! :biggrin:


----------



## panda

thats awful news, be sure to let us know when youre back up and running.


----------



## ashy2classy

Knife arrived today. Will report back when I get a chance to use it. Thanks again, Kipp!


----------



## Kippington

panda said:


> be sure to let us know when youre back up and running.


I'm back baby! 

I've been in timeout for a few weeks, working hard to improve the quality of my fit and finish.

Blade aesthetics are becoming a higher learning priority in my skill tree now that I have confidence in my knife grinds.
Here is the third food release knife I've made (all of them shown in this thread):


You guys have been highly influential to my 'look', and I think it's turned out great! Thanks heaps everyone, I'm really happy with where I am right now and can focus on other things, for at least a little while.

By now I've got to be at least a level 40 blacksmith or something...


----------



## labor of love

You’re working with 52100!!!


----------



## Nemo

Looking bloody amazing!

Can you see the hardening line in person? I'm guessing probably not given that 52100 is deeper hardening.


----------



## TEWNCfarms

Kippington said:


> I'm back baby!
> 
> I've been in timeout for a few weeks, working hard to improve the quality of my fit and finish.
> 
> Blade aesthetics are becoming a higher learning priority in my skill tree now that I have confidence in my knife grinds.
> Here is the third food release knife I've made (all of them shown in this thread):
> 
> 
> You guys have been highly influential to my 'look', and I think it's turned out great! Thanks heaps everyone, I'm really happy with where I am right now and can focus on other things, for at least a little while.
> 
> By now I've got to be at least a level 40 blacksmith or something...




Whoa! Crazy! At first I thought it was just a simple looking Stamped steel but then I saw how it tapered in then came back out for the large bevel (whatever it’s called?), this knife is sick! How much are you letting this go for?! If it’s a knife passaround is there ANY WAY I could get on the list!?!


----------



## TEWNCfarms

Kippington said:


> Thanks Jville, HRC_64 and Ragustoriches!
> 
> Quick update:
> I've recently sold this knife to ashy2classy. I've tidied it up a bit, made a dedicated handle for it etc...
> 
> 
> 
> 
> 
> 
> 
> He preferred the choil to lean forward towards the tip, rather than curving back, so I changed it slightly:
> 
> 
> 
> 
> 
> 
> One thing I've realized; As of yet I've never done a straight-up comparison with another knife. I have access to a factory grind *Masamoto KS 250mm* (shout-out to Marek07 for lending it to me), and I've recorded a quick video with them both in action with the hope it gives a better demonstration of just how much of a difference the 'hook' can make:
> 
> 
> 
> 
> 
> 
> [video=youtube;0HGHpgg5HBs]
> 
> I gotta admit, when I go back to re-watch the video it looks like I'm using different techniques on each knife to encourage food to stick to the KS... I promise that's not the case at all. What's really happening is the food sticking to the KS changes the balance of the long and light knife with every cut. It throws the center of mass far forward making it harder to control and keep consistent rhythm, slowing me down (that's part of the appeal of the heavier workhorses, it's easier to ignore the changing weight of a heavier knife if food sticks to it). I also hate it when food falls _backwards _into the path of the knife again, and gets randomly re-cut. I try to stop it from happening with the KS and it slows me right down.
> When none of this is a problem I can really get into the groove and, instead of slowing down, I begin to speed up.
> 
> I love using this hook grind! It's a lot of fun to use and I should really should look into copying/repeating the results. It took many hours of back and forth testing between the grinder and the chopping board to get it to this stage. It's taught me a _huge_ amount about grinds in the process and there are probably a few people out there that wouldn't mind owning a knife like this for themselves.
> 
> I should also mention, when I said this earlier (in a different thread):
> 
> 
> 
> Some people have referred to this, believing I've been working on another project, but in fact I was talking about the development of the knife in this thread. This grind is enough work as it is haha!




That is awesome brother! Keep up the amazing work! As marek said, you Need to patent this before shun or wustof steal it from you! Again, if you’re looking to sell any of your prototypes or at least doing passarounds PLEASE keep me in mind!


----------



## Kippington

I doubt you can patent a knife grind!

This one is going to Nemo. No hardening line sorry, I chickened out of trying to do it that way. The stock was getting thinner after all the thermo-cycling and I didn't want to risk putting it through a water quench.

Yeah Craig, at the recent Melbourne Blade Show I bought some 52100 and Takefu Shirogami Damascus to try. It's been interesting, but there's a demand for the water hardening steels after the passaround thread, so I'm going back to that soon.

I've finally worked out how to polish the hamon too, so it should be good to revisit.


----------



## Jville

Damn kipp that's looking nice, I'm jelly. That's more the finish I was imaging on the hook grind


----------



## Kippington

Yeah sorry Jville, I had no idea how to polish the knife when I made the first one. It turns out I needed to construct the blade in a different order to make it possible.

Yours will always be the first!


----------



## Marek07

Kippington said:


> I'm back baby!
> 
> I've been in timeout for a few weeks, working hard to improve the quality of my fit and finish.
> 
> Blade aesthetics are becoming a higher learning priority in my skill tree now that I have confidence in my knife grinds.
> Here is the third food release knife I've made (all of them shown in this thread):
> 
> 
> You guys have been highly influential to my 'look', and I think it's turned out great! Thanks heaps everyone, I'm really happy with where I am right now and can focus on other things, for at least a little while.
> 
> By now I've got to be at least a level 40 blacksmith or something...



Looking really good there Mr K! You've always made very nice cutters, now they're lookers as well.
Put me down for a couple please.


----------



## panda

I'm very curious how your treatment of 52100 turns out


----------



## TEWNCfarms

Kippington said:


> I doubt you can patent a knife grind!
> 
> This one is going to Nemo. No hardening line sorry, I chickened out of trying to do it that way. The stock was getting thinner after all the thermo-cycling and I didn't want to risk putting it through a water quench.
> 
> Yeah Craig, at the recent Melbourne Blade Show I bought some 52100 and Takefu Shirogami Damascus to try. It's been interesting, but there's a demand for the water hardening steels after the passaround thread, so I'm going back to that soon.
> 
> I've finally worked out how to polish the hamon too, so it should be good to revisit.



Why not? It is unique design of something, people patent the dumbest **** that’s just a minor difference in something else. I’m sure you could do it. It’d cost a Lot of money though (I believe)


----------



## milkbaby

Third time's the charm they say...


----------



## Nemo

I have been using and comparing the 52100 240 (plus a bit) mm hook grind knife for a couple of weeks now.

The blade finish is great. It's semi-mirror. There are a FEW barely visible short linear coarse grind marks in the depths of the hook recess (about halfway up the blade) which are really only apparent because or the overall quality of the remainder of the finish. Given that Kip was not confident about being able to polish the hook crevice at all and this one was his first attempt at polishing it, I'm super stoked with the finish. The hardening line is not visible. The spine and choil are beautifully rounded, the choil rounding formed to fit the middle finger on the right blade face. The pine handle has a darker wood ferrule and an aluminum spacer. It's well tapered and comfortable.

The profile has a decent flat spot just in front of the heel, then a curve up to a mid height tip (I was given the option of a low, mid or high tip). The spine tapers along its entire length, more pronouned at the very thin tip. The knife is moderately heavy and quite blade heavy.

This knife is very thin behind the edge but the top of the hook bevel is less thin. Overall performance in hard tall foods is like a middleweight, just a tiny bit more wedgey than my (new grind) Gengetsu 240, maybe a little less than my 270mm Shiro Kamo Syousin Suminagashi. Much less than my Mizuno Hontanren wide bevel and my Yoshikane SKD Tsuchime.

Food release is amazing. Overall stiction in wet food is less than my (quite workhorsey) Mizuno and slightly less than my (very workhorsey) Yoshikane (still need to test it vs my Watanabe). Fine diced carrot, onioin and zucchini simply falls off the blade after the hook bevel.

Edge retention is probably in between well HT examples of white and blue. Which I guess is what you'd expecet given the steel's composition. I have stropped it twice. Once to repir a very minor edge ding (edge vs faucet, visible only as a glint of light on the edge), which came out with two stropping passes on a dry 8k Kitayama. Just yesterday after 2 weeks of continuous home use, I thought that the edge could do with a refresh. Once again, 2 light stropping passes on dry Kitayama bought the edge back to life. I reckon it's gonna be super easy to sharpen.

Reactivity is mild. It formed a grey-white patina after a bit over a week.

To me, this knife performs like a middleweight with the food release of a workhorse grind. I really like it. Really like it. The grind and profile are super and the fit and finish on the blade is very good. Well done, Kip.


----------



## Kippington

I'm glad you're enjoying the knife!
Awesome write up, feedback is always greatly appreciated. Cheers!


----------



## Nemo

Comparison of blade adherence to:
1) Gengetsu SS:





2) Yoshikane Tsuchime SKD:





Also a spine shot depicting taper:


----------



## Nemo

I note that adherence of food to the blade and stiction in wet food are two different aspects af food release which don't necessarily go together. The hook grind seems to do them both well.

There was some question as to whether the hook would catch on onioin during horizontal cuts. This hasn't been an issue so far in my use.


----------



## rick alen

You can patent anything that [can successfully be shown] to have uniqueness/improvement of function, the law firm has a lot to do with this. Takes 3-4 years to actually get the patent, and figure at least $15K lawyer and patent office fees, and possibly double that depending on the number of patent reviews it has to go through. No money back if rejected. Think it worth it?


----------



## Kippington

$15k and all that work _for a maybe_? Wow sod that, unless someone wants to spot me the cash! 
I'm actually curious: If anyone _does _attempt to copy this grind, what method will they come up with to polish it? It's a pain in the ass haha!




On a separate note, I've had some interest from the German KKF for a passaround. They'd like to compare this hook style of food release against some of the other major players - Dalman, Xerxes and the like.
It got me thinking, if I make one for them I should definitely make a second passaround for this forum too. Fit and finish would be worse than above. Maybe just for fun I could call a lottery for the last spot in the rotation, whoever ends with it would get to keep it.

The thing is I get requests for custom orders faster than I make the knives (I'm a slow hobbyist maker), and I cant just ignore those. 
I gotta work this out...


----------



## rick alen

Oh btw, it's too late for a patent anyways as you have already publicly released the design.

You can try electropolishing, minimum batch quantities are typically around $200, and that would cover a pretty large batch of knives, they will possibly do some free sample pieces for you. The EP house can tell you what sort of finish you need to rough it to, I think a 220 grit sandpaper would be OK, possibly not even that fine.


----------



## merlijny2k

Seek out a company that can drop-forge the blades and launch a kickstarter that actually rocks the whole kitchen knife world. That way the whole world can benefit.

Don't forget to include a lefty version though.


----------



## panda

kip when are you going to give KU finish a try? =P


----------



## Nemo

From my discussions with Kip about this, I think that the main issue with Ku is that it's difficult to maintain a constant width blade road when the knife tapers as much as Kip's blades do (you have to constantly adjust the angle of the blade road as you go down the length of the blade).


----------



## Kippington

Yeah I tried it at one stage and it didn't work out with the way I taper the spine on my blades. As Nemo recalls, it has a lot to do with this shape of shinogi looking wrong... even though it's fine.
KU would look really odd on this grind:








You simply can't taper a blade like this without making a KU blade look like crap.
I have similar problems with low layer pattern-welded steel and san-mai construction.


----------



## panda

what if you did faux ku after grind like that blueing stuff that jon does for ku rehab?


----------



## Kippington

That wouldn't be a bad idea, but I'd need to look into the chemicals. Got any leads?


----------



## McMan

IIRC I remember reading Dave having some good luck with gun blue. Gun black is also available.

https://www.brownells.com/gunsmith-...-chemicals/gun-blue-black-kits-prod27174.aspx


----------



## Jville

Kip's knifes do have really great taper, probably as good, if not the best, as any I've used


----------



## Nemo

Jville said:


> Kip's knifes do have really great taper, probably as good, if not the best, as any I've used


This is also my experience.


----------



## panda

i want to see someone try the gunblack!


----------



## Nemo

Not sure if it's even an issue but is gun black/ blue known to be food safe?


----------



## Barmoley

The blue is patina/rust process so should be.


----------



## Nemo

Is it just an acid?


----------



## Barmoley

Sort of, it is usually selenium dioxide based compound. Selenium dioxide can be dissolved in water to form selenious acid.


----------



## Nemo

Might actually be good in Oz...

Australian soil is notably deficeint in Selenium IIRC [emoji6]

Edit: Disclaimer: The author does not suggest that Australians consume Selenium based blueing or blacking solutions [emoji848]


----------



## RDalman

The small knife paired with the cleaver here is chemichally gun blued. The cleaver have "real" ku from the hardening by it's spine.

https://www.instagram.com/p/BogrZzgBosG/?utm_source=ig_share_sheet&igshid=9pb37nru83qy

Edit: birchwood casey super blue.


----------



## ecchef

Martell did a nice blueing job on a Forgie conversion of mine. Hasn’t killed anyone yet.


----------



## Barmoley

How well does it work against reactivity, is it more stable/durable than normal patina? In theory it should be.....


----------



## Pensacola Tiger

Nemo said:


> Not sure if it's even an issue but is gun black/ blue known to be food safe?



Not if you drink it. When used to blue a metal surface, it presents no hazard, AFAIK.


----------



## Pensacola Tiger

Barmoley said:


> How well does it work against reactivity, is it more stable/durable than normal patina? In theory it should be.....



My experience is that it is about the same as a well-developed patina.


----------



## merlijny2k

I tried modifying the grind on a cheap santoku today to see if I could boost performance and test some idea's I had. Knife is a Rosenthal. Very soft chinese steel steel but decent spine thickness and balance and half decent grind to start from. Perfect for my purposes.

I tried to improve performance on food release and horizontal onion cuts. To achieve this I did three things:

I thinned the spine of the knife in the front half.

Ground the left side of the knife flat and very thin.

Put a small widebevel on the right side that stops where the granton edge begins. About 6mm from the edge.

Put a 70/30 assymmetric edge on it.

The results are as follows:

Horizontal onion cuts still suck. Seems like the grantons ruin the smoothness of the cut. Is this normal or am I doing something wrong?

Food release on onion parts is as terrible as can be.

Food release on potato is pretty darn good. Not as good as Kip's grind of course but better than I have seen on some cutting video's with J-knives said to have good grinds by knowledgeable people.

The complete disparity of onion vs potato performance leaves me puzzled. Any thoughts?


----------



## Jville

merlijny2k said:


> I tried modifying the grind on a cheap santoku today to see if I could boost performance and test some idea's I had. Knife is a Rosenthal. Very soft chinese steel steel but decent spine thickness and balance and half decent grind to start from. Perfect for my purposes.
> 
> I tried to improve performance on food release and horizontal onion cuts. To achieve this I did three things:
> 
> I thinned the spine of the knife in the front half.
> 
> Ground the left side of the knife flat and very thin.
> 
> Put a small widebevel on the right side that stops where the granton edge begins. About 6mm from the edge.
> 
> Put a 70/30 assymmetric edge on it.
> 
> The results are as follows:
> 
> Horizontal onion cuts still suck. Seems like the grantons ruin the smoothness of the cut. Is this normal or am I doing something wrong?
> 
> Food release on onion parts is as terrible as can be.
> 
> Food release on potato is pretty darn good. Not as good as Kip's grind of course but better than I have seen on some cutting video's with J-knives said to have good grinds by knowledgeable people.
> 
> The complete disparity of onion vs potato performance leaves me puzzled. Any thoughts?


Perhaps, onions get caught up in the grantons.


----------



## refcast

Kip, have you tried making a grind that:
-super thin behind the edge 
-thick, lightly rounded shoulders like 2/3 spine thickness
-concave from edge to shoulder
-concave face 
(so in total, like a gentle w)

I had a TF like that and it had crazy food release. But it accelerated through the cut. Didn't like that. But it didn't really wedge . . . until I softened the shoulders. Personally, I don't enjoy using the grind because I really like a linear feeling though the cut, but it is one of my top performing grinds I've experienced, as inconsistent as it was.


----------



## Kippington

refcast said:


> Kip, have you tried making a grind that:
> -super thin behind the edge
> -thick, lightly rounded shoulders like 2/3 spine thickness
> -concave from edge to shoulder
> -concave face
> (so in total, like a gentle w)
> 
> I had a TF like that and it had crazy food release. But it accelerated through the cut. Didn't like that. But it didn't really wedge . . . until I softened the shoulders. Personally, I don't enjoy using the grind because I really like a linear feeling though the cut, but it is one of my top performing grinds I've experienced, as inconsistent as it was.


Sorry, I missed this post till just now. Could you please show me what you mean with a diagram? I don't quite follow from your description alone.


----------



## refcast

I couldn't get the proportions quite right, but this is an over-exaggerated representation of my particular 270 TF denka wa-gyuto (don't have it anymore though). Just make the shoulders less fat, spine less fat, concavity a bit less extreme. I can't seem to do that with my skills on autodesk though.

The thing is though, that the grind changed in proportion a bit along the blade but that somehow allowed it to cut pretty much the same way. Perhaps because if it was consistent it might not have worked as well.

By crazy food release I mean, slices of potato fell off. Brunoise red bell peppers fell off after the cut, or rather, very little stuck on the upstroke of a push cut.


----------



## Nemo

Is this an S grind?


----------



## merlijny2k

Nemo said:


> Is this an S grind?



S-grind has the part behind the edge convex rather than concave.


----------



## ecchef

Looks similar to an old Takeda grind. Somewhat.


----------



## ecchef

Busse used an interesting grind on some of their blades:




Like a series of shallow Kippington hook grinds in parallel. I wonder how that would work on a gyuto?


----------



## refcast

For my instance of knife, compared to takeda grind:

shorter blade height
thinner behind edge and concave, like kochi
slight concave blade face, less concave than takeda but with hammer indents

from what i've seen online, highest performance teruyasu fujiwara grind is like kochi, most workhorse/wedgey is just thicker behind edge.


----------



## HRC_64

Concave oftentimes sucks IMHO because of the steering, 
you want convex BTE because its more manuerable 
and cuts better in product.

If you sharpen kitchen knife a razor blade or a scalpel 
its "sharper" than a kitchen knife sure, but its too grabby
and it cuts food like dog-****...butchers also talk about
"knives being too sharp" ... its vary appernt in meat

I know this is all opinion (/personal preference) etc, 
but I think its important to think thru...
ie, just what is "high performance" etc....


----------



## ecchef

I think those butchers are probably referring to ‘toothyness’ rather than sharpness, or maybe a thin edge that deforms on contact with bone. I don’t really break down primals anymore, but for me there’s no such thing as a too sharp butcher knife.


----------



## Kippington

I'm guessing 'too sharp' might have something to do with the knife cutting through things you don't want it to go through.
I sometimes find these two jobs to be annoying as hell with a super sharp knife, as it will simply cut through the thing I'm trying to separate...








But this is going a bit off topic. I don't think a concave grind has anything to do with this.


----------



## HRC_64

Kippington said:


> But this is going a bit off topic. I don't think a concave grind has anything to do with this.



You've got the basic idea covered here. 

If you look at a single beve, they use a clamshell (convex)
on the bevel, not a hollow for this exact reason.

The convexity in a single bevel isn't for food release,
because the slice is typically opposite the convexity.

The convexity is for "edge release" for lack of a better way to say it.
its not technially as sharp/acute...but its better handling when it cuts.

It "seems sharper" because its more controlled, and better handling
but its differnt property than edge refinement or bite.

(Simialrly the curve of the edge is there for the same reason, 
but that's probably getting off topic).

Hope this is helpful explanation.


----------



## HRC_64

Note the bevel is not releasing the product, the slice is agains the ura (hollow side),
and the lack of surface area actually helps reduce sticktion.

>https://cdn-b.william-reed.com/var/...lleting-a-fish-with-a-Japanese-deba-knife.jpg

If you watch a fishmonger with a deba, similalry the bevel goes against the spine
(or the table side) when doing the filet cut (typically from right to left),
it isn't releasing off the bevel... because that side is sort of immovable.


----------



## Kippington

HRC_64 said:


> The convexity in a single bevel isn't for food release,
> because the slice is typically opposite the convexity.


It's used both ways, slicing off both the left (0:10) and the right (1:10):

Also, it was the ura on the table side when he was skinning the fish, not the bevel... albeit a different usage from filleting off the spine.

But hey, I don't know enough to say a whole lot about single bevels. I'm very much a double bevel guy!


----------



## HRC_64

Kip the 'typically' wasn't meant to imply every possible cut,
each knive has to be able to cut vertically as well.

The relation of convextiy to control is about steering, and assumes
you are making a cut that needs to be "steered"...
either because avoid or closely follow an object...
like a spine, the grain in flesh, the curve etc of the radish

A vertical cut, however being a straight cut, in theory
is no problem with a flat-side edge against product,
or a pure flat grind knive.


----------



## panda

Kippington said:


> I'm guessing 'too sharp' might have something to do with the knife cutting through things you don't want it to go through.
> I sometimes find these two jobs to be annoying as hell with a super sharp knife, as it will simply cut through the thing I'm trying to separate...
> 
> 
> 
> 
> 
> 
> 
> 
> But this is going a bit off topic. I don't think a concave grind has anything to do with this.


Yes!! Especially skinning fish, so many times I've cut right through the damn thing instead of it peeling..


----------



## Kippington

Our fellow knife nuts over on zee German forums have asked me to make a hook grind knife for a passaround. They'd like to compare it against some of the major players in the area of food release:



_(Dalman Knives and Xerxes)_

This should be interesting... 
I hear they are brutal in their criticisms, even going so far as to look at knives under a microscope to find faults...



_(Kamon Custom)_

I had two on order so I've gone and made them at the same time:




















I still gotta make the handles.
The other makers would laugh if they found out how long it takes me to grind and polish one of these suckers.  It takes me about 4 times longer than a standard grind... but at least I'm really happy with the consistency and how they're turning out.

I'm not gonna lie, I'm super interested in what these guys have to say!


----------



## Chicagohawkie

I’m up for a passaround! Looks awesome!


----------



## Michi

If it's possible to be part of the pass-around in Australia, I'd love to try this!


----------



## Kippington

Well one of the Germans asked to go on my list a few months ago, and he's buying this knife for himself to own. The passaround will be organised through his end, and I highly doubt he would appreciate me sending his knife on a quick detour to someone else before he gets to hold it!

Sorry!


----------



## Nemo

More 52100... cool!

I look fwd to seeing what they say.


----------



## Barmoley

Very interesting. How are you liking 52100 as compared 1095 and W2.


----------



## Kippington

Barmoley said:


> Very interesting. How are you liking 52100 as compared 1095 and W2.


Earlier in this thread I mentioned I can't use a shallow hardening steel on this grind, so it ruled out W2 and 1095 for these particular knives.
I do like 52100 though. I don't get to try my own knives much as I'm backlogged on making them for other people!


----------



## RDalman

Awesome Kip! The germans are much much nicer and kinder and even respectfully writing than what one might get the image of at first. I believe they will love it. And 52100, such a treat to work with good call.


----------



## Michi

Kippington said:


> The passaround will be organised through his end, and I highly doubt he would appreciate me sending his knife on a quick detour to someone else before he gets to hold it!


Yes, fair enough. I shall live…


----------



## Nemo

Barmoley said:


> Very interesting. How are you liking 52100 as compared 1095 and W2.





Kippington said:


> Earlier in this thread I mentioned I can't use a shallow hardening steel on this grind, so it ruled out W2 and 1095 for these particular knives.
> I do like 52100 though. I don't get to try my own knives much as I'm backlogged on making them for other people!


I have a Kip Hook Grind (I keep wanting to say "Trick Pony") in 52100 and a laser in 1095. Both are easy to sharpen, have a silky feel on the stones and take as sharp an edge as I can produce. I haven't sharpened them side by side but my impression is that thay are similar on the stones. The 52100 edge certainly seems to last a little longer and it doesn't patina as much.


----------



## Nemo

Michi said:


> Yes, fair enough. I shall live…


Or you could commission one [emoji16]

You won't be disappointed.


----------



## Kozuka

Kippington said:


>



That looks super interesting. Are there videos showing off this grind? And the food release? I'm one of those german nerds btw ;P

Looking forward to those knives popping up over here.


----------



## Kippington

Guten Tag!
There are some good videos earlier in this thread demonstrating how the grind works as I was developing it.
There's also a 60 second Instagram video which I don't think I've posted here yet:
https://www.instagram.com/p/BohCDQRhyPy/


----------



## Xenif

RDalman said:


> The germans are much much nicer and kinder and even respectfully writing than what one might get the image of at first.



Sure sure that's what they always say ... [emoji13] 
But seriously I want to know the results of this comparison/pass around, do we have members here that are part of that forum and can translate the results?


----------



## Kippington

Google Translate does a pretty good job I think. I'm not sure if the following link will work properly for everyone, but it's worth a try.
https://translate.google.com/translate?sl=de&tl=en&u=http://kochmalscharf.freeforums.net/


----------



## milkbaby

Kippington said:


> Google Translate does a pretty good job I think. I'm not sure if the following link will work properly for everyone, but it's worth a try.
> https://translate.google.com/translate?sl=de&tl=en&u=http://kochmalscharf.freeforums.net/



"The rules for a nice togetherness" 

Edited to add:
"The 'Optimize My Groin Challenge'" 
https://translate.googleusercontent...700248&usg=ALkJrhjFqyiN4yPGusyRqUs829ChC84vIg


----------



## silverneedle

That is an awesome idea. Something i tried was to form a small ridge (of milliput) about 2cm from the edge along the length of a cleaver. its not enough to cause much noticable difference in wedgeing but it does push the food away and stop it sticking mostly. I think the same could be done with a tidy bead of weld too. The dip away the at the handle end is to make space for fingers and push the food away that travels backwards while cutting.


----------



## Kippington

Very interesting idea. Can you post a video of it in action?


----------



## parbaked

Kippington said:


> Very interesting idea.



I saw Mark Militello use a knife with holes and a ridge to slice cucumbers on "In Julia's Kitchen with Master Chefs" in the 1990s.
She asked him about it and he liked it for food release.
It looked similar to the Wusthof Ridge knife.


----------



## Xenif

We are edging ever closer to the perfect food release grind ... I propose an S grind + holes, the patented S-Hole grind has been born!


----------



## silverneedle

Heres a short clip of that cleaver. Broccoli stalk is not that sticky but it does work with things like cheddar or leeks too. In fact its great if there is alot of cheddar to slice. Excuse the shaking camera and rubbish quality but you get the idea.


----------



## Kippington

Thanks for the video. It's an effective method for sure. It still runs into the same problem all the food-release grinds have, which is that the higher you place the bump, the less effective it is. I went into more detail on post
#65 *here* in this thread.
If you lower the bump closer to the cutting edge, it would start to resemble the step on many of the S grind knives.
Very cool idea with moving the bump closer to the handle to discourage food touching your hand. This is the only kind of geometry a trick like this would work on.


----------



## Michi

parbaked said:


> I saw Mark Militello use a knife with holes and a ridge to slice cucumbers on "In Julia's Kitchen with Master Chefs" in the 1990s.
> She asked him about it and he liked it for food release.
> It looked similar to the Wusthof Ridge knife.


It seems to work fairly well. But I can't get over how butt-ugly that knife is…


----------



## Michi

There is the Wüsthof vegetable knife, which seems to work along similar lines of thought:

https://www.amazon.com/dp/B00BD6N4CG/?tag=skimlinks_replacement-20

It's butt-ugly, unfortunately. What you are trying has much better aesthetics and might well work better. Please keep us updated. This looks like a really promising idea!

When cutting food, I'd try some raw potatoes, as well as fruit such as pineapple and watermelon. These tend to be among the foods that stick a lot. Banana might be another one worth experimenting with.


----------



## Dhoff

Binge read the thread... Now I feel like watching a great tv series, I want to know the ending!

Wonder how bumps om the blade would Work... Jmmm


----------



## stephen129

Fascinating thread. Thanks Kip.


----------



## Tanalasta

Fascinating thread. Kip makes good knives and pursues the science behind them. (n=1 happy customer here)


----------



## rick alen

I know I've said this before, but even though shallow grantons do not make food fall off, they do decrease slicing stiction.


----------



## Kippington

Uh-oh... 
It seems another maker has found this thread, he even calls it a hook grind.
https://www.instagram.com/p/B6gl81ZHMv2/


----------



## Michi

Kippington said:


> Uh-oh...
> It seems another maker has found this thread, he even calls it a hook grind.


You'll have to call yours 'the original hook grind" now


----------



## labor of love

Kipp, have you made a double hook yet?


----------



## madelinez

Just wait until it turns up on those ads for crappy fake japanese knives.


----------



## Kippington

labor of love said:


> Kipp, have you made a double hook yet?


Nah it wouldn't make sense unless you do your cuts holding the knife with both hands haha.
I have made a few left handed ones though, so there's always that option


----------



## M1k3

labor of love said:


> Kipp, have you made a double hook yet?



Quadruple hook!


----------



## Carl Kotte

Kippington said:


> Uh-oh...
> It seems another maker has found this thread, he even calls it a hook grind.
> https://www.instagram.com/p/B6gl81ZHMv2/



Yeah I saw that and thought about asking him whether he shouldn’t at least mention you, out of courtesy or what not. Then I thought that you might be friends and it would be pedantic of me to make such a comment if you were. Now I think I should have acted on my gut feeling. At least this one time. [emoji848]


----------



## Kippington

Nope - Kamon never talked to me about it.
It would've been real nice if he mentioned it was my idea, but at least he acknowledged it by its real name of almost two years now...


labor of love said:


> Fish hook grind haha


----------



## labor of love

Did you just necro quote me?


----------



## Kippington

You gave birth to it's name! 
Kamon never mention me, but your influence lives on...


----------



## Matus

Kippington said:


> Uh-oh...
> It seems another maker has found this thread, he even calls it a hook grind.
> https://www.instagram.com/p/B6gl81ZHMv2/



I do not see him claiming it being his invention. Plus he has been doing different versions of more complex grinds for a while.


----------



## labor of love

I also coined the term “ work pony” don’t let @panda or anyone else take the credit!


----------



## labor of love

Imitation is the sincerest form of flattery.


----------



## Kippington

Matus said:


> I do not see him claiming it being his invention


I never claimed he did.
The situation _*is*_ interesting though, from the point of view of this thread.



labor of love said:


> I also coined the term “ work pony” don’t let @panda or anyone else take the credit!


I swear that was panda!


----------



## labor of love

Maybe he thought you stopped making knives?


----------



## Kippington

I'll get to your order one day Labor...


----------



## labor of love

Kippington said:


> I never claimed he did.
> The situation _*is*_ interesting though, from the point of view of this thread.
> 
> 
> I swear that was panda!


We do have KKF “after hours” sessions so to speak. I may have slipped an idea of the work pony and he ran with it.


----------



## labor of love

Kippington said:


> I'll get to your order one day Labor...


Haha. I’m looking forward to it, as always.


----------



## Matus

Kippington said:


> I never claimed he did.
> The situation _*is*_ interesting though, from the point of view of this thread.



No you did not and nor was it my intention to suggest that. He might indeed have picked that name in this thread - what’s wrong with it?


----------



## Kippington

You'e completely lost me.


Matus said:


> He might indeed have picked that name in this thread - what’s wrong with it?


I don't see anything wrong with it. Do you?


----------



## Matus

I think I must have misunderstood you in the first place. Sorry for that. Let me re-read the relevant posts.


----------



## ma_sha1

My ideal knife is a grind somewhere between work horse & work pony. I am naming it the “work hoony” grind, don’t let anyone take the credit away from me


----------



## Kippington

ma_sha1 said:


> My ideal knife is a grind somewhere between work horse & work pony. I am naming it the “work hoony” grind, don’t let anyone take the credit away from me


The *Fat Pony*


----------



## Carl Kotte

Kippington said:


> The *Fat Pony*



How’s food release on that one?


----------



## Barmoley

Carl Kotte said:


> How’s food release on that one?


Clearly not good all the food stays with it.


----------



## Carl Kotte

Barmoley said:


> Clearly not good all the food stays with it.



[emoji854] Despite the hoof grind, it seems you’re right


----------



## M1k3

What about a svelte Clydesdale?


----------



## ma_sha1

Kippington said:


> The *Fat Pony*




Lol, that is a Rhino with the horn cut-off


----------



## panda

labor actually came up with the phrase work pony, i was just the one who pushed it to become a thing.


----------



## Kippington

It's definitely catching on in general use. I see it a lot these days, and it's use isn't restricted to my stuff either.


----------



## nakneker

Kippington said:


> Uh-oh...
> It seems another maker has found this thread, he even calls it a hook grind.
> https://www.instagram.com/p/B6gl81ZHMv2/


 
Imitation truly is the purest form of flattery. He is either naive or devious. All I know is the my Fishhook grind 240 is one my most cherished knife. I ordered it out of curiosity, it went into the keeper pile after 2-3 minutes of use.


----------



## McMan

Matus said:


> No you did not and nor was it my intention to suggest that. He might indeed have picked that name in this thread - what’s wrong with it?


respect where respect's due, no?


----------



## Carl Kotte

McMan said:


> respect where respect's due, no?



Sounds right to me.


----------



## Kozuka

Kippington said:


> Uh-oh...
> It seems another maker has found this thread, he even calls it a hook grind.
> https://www.instagram.com/p/B6gl81ZHMv2/



A little background to his: At the big EU knife meeting in Amstetten I showed him the Version you made for MB and he was really intrigued on how you did it, since he couldnt figure it out for weeks or even months. He was very impressed by the execution and perfection of the Hook and knife in general I guess. As we visited his shop the day after he showed us how he thinks you do it on the belt and how he always wanted to make a concept knife from it to try to improve on his S-Grind. Ben really is a honest nice guy and I dont think he has any bad intentions or means anything wrong by it. Anywayn, I will shoot him a message letting him know about how you feel about it


----------



## Kippington

Kozuka said:


> A little background to his: At the big EU knife meeting in Amstetten I showed him the Version you made for MB and he was really intrigued on how you did it, since he couldnt figure it out for weeks or even months. He was very impressed by the execution and perfection of the Hook and knife in general I guess. As we visited his shop the day after he showed us how he thinks you do it on the belt and how he always wanted to make a concept knife from it to try to improve on his S-Grind. Ben really is a honest nice guy and I dont think he has any bad intentions or means anything wrong by it. Anywayn, I will shoot him a message letting him know about how you feel about it


I'm not sure if you understand how I _actually _feel about it - I haven't made my thoughts clear in this thread yet. In fact, I'm guessing some people misinterpreted the _"Uh oh"_ as an "_Oh *no*"_.

I don't mind him trying it at all. The truth is, if he had simply asked me how to do it, I would've told him. Hell, I even explained how to do it earlier in this thread - but that could take all the fun out of him trying to reverse engineer it.
I would've liked it if he had mentioned my work and research, but it wasn't a requirement by any stretch... All makers copy certain aspects off previous works.

I enjoyed creating something new and documenting the progression in this thread. It was a blank slate when I started out, I had no idea if I'd end up with something viable. The idea that I've made something worth copying is pretty cool, and honestly if it worked efficiently it was never going to be something I could keep to myself. It would be foolish of me to think otherwise.

The _"Uh oh"_ was simply my thinking out loud - My work has grown up and moved out of home: this thread to be more precise. Further enhancements or modifications might occur and never make it back to this forum.
I'm happy Ben called it a by it's name - the hook grind. If he called it something else I would've been annoyed, simply because terms that overlap in meaning create confusion.

Everyone knows the most common food release grind, the one pictured below. Can anyone tell me what it's called, and who the first person to do it was? I sure don't know.


----------



## KAMON Knives

Hey guys, 

I didn't intend to offend someone by not mentioning names. I'll try to explain what happened so you understand my point of view:

Like @Kozuka said, I saw @Kippington's work in person at an KMS forums meeting in Austria. I was always wondering how he does this kind of grind, always wondering about it's performance and of course always curious to do it myself. 
I never found the time until I had a messed up S-grind blank and just started to do what I thought was necessary to achieve this grind and it worked out. 
I guess at least... looking just at the performance and not F&f of course. It's a prototype after all. 

Now there's no secret where I got my inspiration from. It clearly was from kippington and I'm not shy in stating so! 
I have to be clear though - I never asked how he does it nor did he tell me on his own. I also didn't watch any videos or something like that if there even exist any, and I also don't know if he is the first who did that grind nor if he does it like I do. 

IMHO it's different after all as it's not a hook grind but an "s-hook grind". (In my opinion also the food holding side is important for the performance of a knife and therefore food release on the food holding side is important too.) 

I hope you see why I had a problem to say thank you but then again real clear - the inspiration came from kippingtons knives.
If the majority here thinks it's a bad thing to not mentioning him then I can always do that if I ever finish such a knife. I really don't mean to do anyone any harm nor do I intend to be seen as a copycat. After all I always try to advance stuff and except for the similar concepts it's somewhat different from what kippington does. Don't you think?

Regards 

Benjamin


----------



## KAMON Knives

Haha sry @Kippington... Now I did insult you by calling it an s-hook grind. (pls don't take this too seriously )


----------



## Kippington

Nah its all good, the _"hook"_ was still in there! 


KAMON Knives said:


> I have to be clear though - I never asked how he does it nor did he tell me on his own. I also didn't watch any videos or something like that if there even exist any, and I also don't know if he is the first who did that grind nor if he does it like I do.


If you're interested, the entire history of its creation is pretty much documented here in this thread.


----------



## KAMON Knives

And I thought about it right now. I'll just mention you as soon as I got something finished. Don't want to be seen as the originator of this idea and I took the inspiration from you which I'm not afraid to state. Sry for not mentioning you in the first place. 

Regards 

Benjamin


----------



## Carl Kotte

I say, another christmas miracle on KKF - where dreams come true [emoji268][emoji16][emoji1303]


----------



## Kippington

KAMON Knives said:


> And I thought about it right now. I'll just mention you as soon as I got something finished. Don't want to be seen as the originator of this idea and I took the inspiration from you which I'm not afraid to state. Sry for not mentioning you in the first place.


Cheers!

Good luck working out how to polish the bastard!


----------



## Dhoff

Wow this thread is suddenly lively. I personally love that this grind ideal is being explored, who knows what mutant babies Will be norm?


----------



## Barmoley

What do you guys think of the longevity of these grinds? For most of us here not an issue since we have a million knives and never really change the profile and height much. For a main knife for a pro though, every time you sharpen a hook grind, you make the hook less pronounced since I assume you sharpen the hook side as a short wide bevel.


----------



## M1k3

As long Kippington gets credit, even if not on a big billboard, I'm not getting out the pitchforks. Great job to both of you.


----------



## KAMON Knives

I guess you can eventually grind out a hook grind as you can grind out an S-grind @Barmoley but the knife won't be defect then. It will just be a "normal" convex (or whatever) ground knife then.

About how long this will take in professional use it strongly depending on the user I'd say.


----------



## Nemo

It essentially depends on the height of the hook (and obviously how much steel you grind away).

The higher the hook, the less food release benefit, so there is a definite tradeoff between longevity of the grind and food release in this grind.


----------



## Barmoley

Thanks. Both answers make sense, like I said not a real issue, just a curiosity of mine. Always wonder about more complex grinds.


----------



## Kippington

Nemo said:


> It essentially depends on the height of the hook (and obviously how much steel you grind away).
> 
> The higher the hook, the less food release benefit, so there is a definite tradeoff between longevity of the grind and food release in this grind.


Spot on.
All the hook grinds I've made so far have had to take this into consideration. I've never made one that was designed for performance alone, there's always the element of longevity / life span which decreases the food release.
I mentioned this briefly two years ago, when I posted this picture:


Kippington said:


> The height of the step has a huge effect on the efficiency of food release. The lower I make it, the better the release while also decreasing its ease of thinning.








An interesting side effect of this is that as you sharpen the knife over time, the hook actually becomes _*more effective*_, until the point you reach the step.
The one Kamon made has a much lower step than what I've been doing (about half the height) allowing it to out-perform mine, but at the cost of the effective lifespan of the hook. It doesn't matter though because he was making a prototype.
__________

On a related note - If I make a passaround for this forum, do I go all out and grind it for performance alone or do I go for a more realistic lifespan model? You gotta admit, it would be fun to mess around with maxed out performance if you didn't need to worry about the keeping and maintaining of the knife... it would be a tad unrealistic though.


----------



## labor of love

The correct answer is that if you make a pass around knife you make it left handed.


Seriously though, OOTB performance is what I think most would be interested in seeing.


----------



## Michi

For a pass-around, I think a middle-of-the-road version would be best. Most people will never have used such a knife before; something that doesn’t over-emphasize one aspect would make the most balanced impression.


----------



## ian

Agreed. I’d try to give people the most honest impression of what they should expect from the knife, rather than its max potential. Count me in if the knife comes to the US.


----------



## labor of love

What exactly is Max potential I think is debatable.


----------



## gogogo545

Double the hook, problem solved  jk


----------



## labor of love

Might as well make a 15mm tall hook and a 25mm tall hook. Double the pleasure double the fun.


----------



## Michi

@Kippington If you do a pass-around, please put me on the list. I really would love to try that knife!


----------



## madelinez

Me too!


----------



## ma_sha1

Me three


----------



## Dhoff

gogogo545 said:


> Double the hook, problem solved  jk



Might be a joke, but would IT be possible in theory? A Hook with a hook above ready for action when the blade is thinned enough? 

Quadroble Hook grind? Just think of the polishing the Maker would enjoy


----------



## Kippington

It's possible to make the thing with multiple ridges, but it would look bloody ridiculous! I'd call it a _"gill"_ knife.




I swear I've seen a knife out there with multiple ridges, but I'm not even going to try find the picture again.
Polishing it would take 90% of the time to make...


----------



## McMan

Kippington said:


> It's possible to make the thing with multiple ridges, but it would look bloody ridiculous! I'd call it a _"gill"_ knife.
> 
> 
> 
> 
> I swear I've seen a knife out there with multiple ridges, but I'm not even going to try find the picture again.
> Polishing it would take 90% of the time to make...


Xerxes did one (middle). I think technically it is a Z-Z-Z-Z-grind.


----------



## Kippington

That's nuts. I have no idea how he did that...
The one on the left looks like it was knapped, like they do with flint.


----------



## madelinez

You just need one of those fancy micro-abrasive blasting machines... what could go wrong


----------



## M1k3

I'm in for a passaround if it hits the U.S.


----------



## Dhoff

Any performance impact if it is not polished?


----------



## Kippington

Dhoff said:


> Any performance impact if it is not polished?


Are you talking about the Xerxes or the hook?


----------



## HRC_64

Dhoff said:


> Any performance impact if it is not polished?



cleaned up from basic machining or the difference between 400 vs 2k sandpaper?


----------



## Dhoff

Both the normal Hook and the Xerxes "Hook" i guess. Just curious


----------



## Kippington

In terms of food release, it only matters where the food touches. Many foods will grip onto mirror polishes like a suction cup, with the exception of wet foods such as cucumber slices which can slide easily on mirror polishes. Lower grit finishes tend to drop most things easier.

That said, low grit finishes tend to be more prone to rust - especially with carbon steels.


----------



## labor of love

I’ve wondered what the ideal finish for a Sujihiki that cuts raw beef primal cuts would be. High grit like Yanagiba? Maybe not. I guess it depends on the “wetness” on the meat being processed.


----------



## Kippington

I don't think it would matter too much for most suji jobs.
The only major thing that comes to mind is thin slices against the grain on something slow cooked. I think a polished finish would help stop the thing from getting shredded.





The Japanese style is to try for a shiny surface on some cuts of fish - A low grit finish could rough it up which might be seen as undesirable.


----------



## Dhoff

Kippington said:


> Are you talking about the Xerxes or the hook?





Kippington said:


> In terms of food release, it only matters where the food touches. Many foods will grip onto mirror polishes like a suction cup, with the exception of wet foods such as cucumber slices which can slide easily on mirror polishes. Lower grit finishes tend to drop most things easier.
> 
> That said, low grit finishes tend to be more prone to rust - especially with carbon steels.



So, a stainless with low grit finish gas Better food release and would require leds Work for the Maker?


----------



## Kippington

Dhoff said:


> So, a stainless with low grit finish gas Better food release and would require leds Work for the Maker?


Yep, but it depends on what you're cutting. The finish has only a small effect overall.


----------



## playero

Why not use a yanagiba? It will release the food to one side.


----------



## Kippington

Yanagiba can be quite thick 20 mm or so behind the edge. A hook grind would go through harder foods easier.
They're kinda designed for different usages.


----------



## Kippington

Food Release - Round 6, another WIP

I made a video showing one of the shortcomings of the normal hook grind, plus a possible solution inspired by chevron-shaped jet engine covers.





I ended the video abruptly because I went on to essentially fine-mince that potato, which was a bit stupid really... 

Lowering the step is also a possible idea, but I feel it would make the grind fatter than it needs to be.
What do you guys reckon - Am I taking it overboard by messing around with the surface below the step?


----------



## Carl Kotte

@Kippington Cool update! Thanks! Your ’chevron’ grind does seem to have an advantage over the hook grind, but are there any noticeable disadvantages too? (I imagine that the ’chevron’ grind is more demanding to produce... but, I’m primarily interested in differences in performance). [emoji16]


----------



## Kippington

Carl Kotte said:


> @Kippington Cool update! Thanks! Your ’chevron’ grind does seem to have an advantage over the hook grind, but are there any noticeable disadvantages too? (I imagine that the ’chevron’ grind is more demanding to produce... but, I’m primarily interested in differences in performance). [emoji16]


Thanks!
There are none that I can think of, off the top of my head.


----------



## ian

Kippington said:


> Food Release - Round 6, another WIP
> 
> I made a video showing one of the shortcomings of the normal hook grind, plus a possible solution inspired by chevron-shaped jet engine covers.
> 
> 
> 
> 
> 
> I ended the video abruptly because I went on to essentially fine-mince that potato, which was a bit stupid really...
> 
> Lowering the step is also a possible idea, but I feel it would make the grind fatter than it needs to be.
> What do you guys reckon - Am I taking it overboard by messing around with the surface below the step?




There's no such thing as overboard. That's impressive release.


----------



## ian

Btw, is the roughness of the bevel on the chevron knife also part of it, or did you just not get around to polishing it yet?


----------



## Chuckles

Wow. That is really impressive release. The design is so purposeful. It reminds me of an F1 race car vs a daily driver. On any given day it is going to blast a daily driver out of the water for those tasks. Long term maintenance and practicality be damned. I know you have that dialed too as I have owned a traditional gyuto of yours. Really great work. I really appreciate how you are pushing the performance boundaries to a new frontier. Like how Mercedes has the best F1 and also the best mass market sedans. The two are inseparable and self supporting. Bravo.


----------



## captaincaed

This thread had been interesting and enjoyable for years running.


----------



## Dhoff

Dann Kip, you need to get a house in EU for vacation make knife making courses and ship knives All over the place.

Thank you for sharing!


----------



## Nemo

Cool idea. It reminds me of a granton grind, only just on the hook.

To me, food realse is two seprate but repated properties:
1) The ability to go through wet foods without excessive stiction (resistance imparted by the surface tension of the water in the food attaching to the blade face).
2) The ability to shed food from the right blade face.

From your video, the chevron grind appears to be even better than the hook at food shedding, but it's not easy to judge stiction accurately from a video. Do you feel that it is any better than the hook grind at resisting stiction?

How will it hold up to sharpening/ thinning?


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## labor of love

I was reminded of Glestain. Little overpriced these days, and overly heavy handle, but actually nice cutters.


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## Barmoley

Kippington said:


> Thanks!
> There are none that I can think of, off the top of my head.


It is not really sharpenble, or do you sharpen the other side, but even then the hook side needs to be sharpened too.


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## Kippington

ian said:


> Btw, is the roughness of the bevel on the chevron knife also part of it, or did you just not get around to polishing it yet?


It was an earlier attempt to roughen up the surface to help food release. Naturally if I'm using the same test piece to try different additions to the hook grind, I have to test the less intrusive methods first.
The roughness didn't help on it's own, but maybe it's adding a little bit to the effectiveness of the chevrons. I don't really know yet, but I'll know soon when I do the chevrons on another knife without a roughed up surface.



Barmoley said:


> It is not really sharpenble, or do you sharpen the other side, but even then the hook side needs to be sharpened too.







This is what the cross section kind of looks like - obviously expanded to a thicker model.
I think it should be fine to sharpen, there's not a whole lot going on different from the original hook grind, and there's a clear unobstructed path all the way to the spine.

I was making four hook grinds at the same time in a batch. I made all of them really thin behind the edge but it seemed to effect all of their food release. This seems to have fixed it, and so in the future I have the option to grind these thinner than other hook grinds I've done in the past with no ill effects.


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## VICTOR J CREAZZI

Great work @*Kippington. *


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## Luftmensch

Impressive! Nice work!

... however....



Kippington said:


> Am I taking it overboard by messing around with the surface below the step?



I guess everyone will have their own limits for "overboard". *For me*... depending on the item... i dont like utility to be maximised beyond the point where it starts to compromise aesthetics. I guess I have limits for "form follows function"?

Your knives are beautifully made and have nice lines. Hook grind included! But adding the chevrons? Not my cup of tea aesthetically 



That said. From an intellectual pursuit point of view, I like how you are pushing food release to the limit. Looking at the design. I some what see it as extending the hook concept to a second plane. The hook grind adds a step, to help with food release, on the plane parallel to the blade _profile_ (say the XY plane). The chevrons extend this to the orthogonal plane (ZY) where the grind is defined.

I guess you want to maximise air gaps behind the edge? I wonder how effective it would be to mill 1-2mm channels every few millimetres down the face of the blade (stopping some reasonable distance above the edge)?


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## Barmoley

Kippington said:


> It was an earlier attempt to roughen up the surface to help food release. Naturally if I'm using the same test piece to try different additions to the hook grind, I have to test the less intrusive methods first.
> The roughness didn't help on it's own, but maybe it's adding a little bit to the effectiveness of the chevrons. I don't really know yet, but I'll know soon when I do the chevrons on another knife without a roughed up surface.
> 
> 
> 
> 
> 
> 
> This is what the cross section kind of looks like - obviously expanded to a thicker model.
> I think it should be fine to sharpen, there's not a whole lot going on different from the original hook grind, and there's a clear unobstructed path all the way to the spine.
> 
> I was making four hook grinds at the same time in a batch. I made all of them really thin behind the edge but it seemed to effect all of their food release. This seems to have fixed it, and so in the future I have the option to grind these thinner than other hook grinds I've done in the past with no ill effects.


I see. I thought the roughness was part of it, so to keep it you would not be able to sharpen on the rough side without decreasing the roughness. Since that was part of a different experiment then irrelevant.


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## Kippington

Barmoley said:


> I see. I thought the roughness was part of it, so to keep it you would not be able to sharpen on the rough side without decreasing the roughness. Since that was part of a different experiment then irrelevant.


Hah, I didn't realise how much confusion the roughness would cause. I'll show you guys what it looks like without the surface marring after I add the chevrons into one of the spare blanks. Coincidentally, this will become the passaround.


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## Luftmensch

Luftmensch said:


> I guess you want to maximise air gaps behind the edge? I wonder how effective it would be to mill 1-2mm channels every few millimetres down the face of the blade



Just for fun... presenting the serrated hook grind:







Detail of the tip:


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## Kippington

I'll leave that one for you to grind!


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## Nemo

Luftmensch said:


> Just for fun... presenting the serrated hook grind:
> 
> 
> View attachment 70483
> 
> 
> Detail of the tip:
> 
> 
> View attachment 70481



Does it come with a chainmail gove to allow you to pinch grip Without shredding your fingers?


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## Luftmensch

Nope 

But you can grate cheese on it


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## Kippington

Luftmensch said:


> But you can grate cheese on it


Nah, there's already a person making these knives.


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## Nemo

Kippington said:


> Nah, there's already a person making these knives.



But not in Australia!

And what else are we going to do with all of our old files in Oz?


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## Michi

Cleaning one of those would be an absolute joy, no doubt…


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## Luftmensch

Kippington said:


> Nah, there's already a person making these knives.





Nemo said:


> But not in Australia!


and only in workhorse grinds.... 

I'll be here all night folks! Come on... that was actually pretty good... Poor CM...




Michi said:


> Cleaning one of those would be an absolute joy, no doubt…



Make a left-handed version with the opposite teeth... then mesh them together!


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## Michi

Luftmensch said:


> Make a left-handed version with the opposite teeth... then mesh them together!


"Patented dual-lock blades, for safe and easy storage and transport!"


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## Luftmensch

Michi said:


> "Patented dual-lock blades, for safe and easy storage and transport!"



Nice idea! I'll start the Kickstarter page!  We can make them out of old stump jump ploughs

Ok... I'll stop... back to @Kippington's food release grind!


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## Kippington

Here's a quick view of the passaround knife, no handle yet...


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## mc2442

If it makes it to the states, I would like to be considered for the list!


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## Kippington

mc2442 said:


> If it makes it to the states, I would like to be considered for the list!


I should probably start a passaround thread to keep it simple.
The new thread is here:
https://www.kitchenknifeforums.com/threads/passaround-kippington-chevron-hook-grind.45384/


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## Michi

That is just amazing. I hate to think how much effort it took add all those scallops and polish them!


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## madelinez

That looks like an insane amount of work....


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## Carl Kotte

Kippington said:


> Here's a quick view of the passaround knife, no handle yet...




That’s crazy! [emoji854][emoji50]


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## VICTOR J CREAZZI

Kippington said:


> .


Until this picture I did not realize that the primary grind was concave. I re read the thread backwards to see if I had missed this change, but could not find anything.


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## VICTOR J CREAZZI

Double post deleted


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## captaincaed

Luftmensch said:


> Just for fun... presenting the serrated hook grind:
> 
> 
> View attachment 70483
> 
> 
> Detail of the tip:
> 
> 
> View attachment 70481


Chelsea?


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## Kippington

VICTOR J CREAZZI said:


> Until this picture I did not realize that the primary grind was concave. I re read the thread backwards to see if I had missed this change, but could not find anything.


I actually thought it was visible in some of the pictures and never brought it up.




Food release alone will never make me happy, I need a knife that goes through food pretty well too. A concave grind helps, but also increases stiction like a suction cup. The chevrons are a countermeasure to that, allowing air in amongst other things.
I'm considering going to convex on the normal hook grind and keeping it concave on the chevron version.


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## Kippington

Michi said:


> That is just amazing. I hate to think how much effort it took add all those scallops and polish them!





madelinez said:


> That looks like an insane amount of work....


The chevrons are not polished on this, but yes it is still a lot of work.

As I make more of these I will continue to improve quality (this is the first one I've made, other than the test piece). I also have to put more thought into the spacing and depth of the chevrons, but at this stage I need to make full knives just to get to the point where I can even begin new tests.
There are little details I haven't talked about yet, like the chevrons getting smaller towards the tip due to the internal taper (decreasing grind angle) towards the tip. The flexibility of thin steel also plays havoc on the accuracy of the things I'm trying to do. Considerations like this make the knife more difficult to make than just the theory alone would indicate. Remember I'm not getting paid to do any of this. 

My main goal for now is to make a passaround which is really fun to use, and I think this one definitely ticks that box.


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## Caleb Cox

So if manufacturability is not a concern, a hollow ground knife with a "rippling" surface would/should be ideal?


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## Kippington

Your description would work, but there's still room to play with angles, thickness and whatnot. I can't be sure exactly on what you've thought up.

We're talking about a sliding scale with food release on one side and food separation on the other. You can try to maximise both, but you'll never hit the "ideal" in a realistic fashion. I'm simply trying to get the best food release I can on a knife with a thin edge.
Other knives might have better food release than my hook-grind (the Glestain comes to mind) but they tend to rely on a thicker convex edge, which I'm trying to avoid. Lasers have always been my favourite grind, and I'm trying to get a similar feeling in the hook.


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## Caleb Cox

I guess the closest visual analog for the surface I'm imagining is the 3D "damascus" pattern stamped/pressed onto some knife blades for aesthetics.


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## Kippington

Got any pictures? I'm not sure how deep these are.
Those little dots on the one I showed a few posts back did absolutely nothing to help release, and they were engraved into the surface with a rotary diamond tool. Moisture in the food tends to fill the shallow gaps, rendering them useless.

If you think about it, the concave grind itself creates a gap with a ridge running down the length of the knife... but it's still not deep enough to stop the food from suctioning onto the face. Thinner slices of food also tend to conform to the gap. The "ripples" on your theoretical surface would have to be of significant depth.


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## Dhoff

Chevron s-hook grind?


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## Luftmensch

Kippington said:


> I'm considering going to convex on the normal hook grind and keeping it concave on the chevron version.



That sounds like an interesting route to take.


By the way, looks like you're going to need this:

https://www.kitchenknifeforums.com/threads/breakfast-potatoes-and-eggs-for-1.45281/


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## Caleb Cox

Kippington said:


> Got any pictures? I'm not sure how deep these are.
> Those little dots on the one I showed a few posts back did absolutely nothing to help release, and they were engraved into the surface with a rotary diamond tool. Moisture in the food tends to fill the shallow gaps, rendering them useless.
> 
> If you think about it, the concave grind itself creates a gap with a ridge running down the length of the knife... but it's still not deep enough to stop the food from suctioning onto the face. Thinner slices of food also tend to conform to the gap. The "ripples" on your theoretical surface would have to be of significant depth.






Unfortunately this is the only pic I have a blade with an effect like what I'm describing. The "Damascus embossments" could be felt by hand but would have to be exaggerated before it would provide air gaps. Maybe a more accurate description of what I imagined would be a veiny surface.


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## M1k3

Hmmm..... Nested fish hook?


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## Dhoff

M1k3 said:


> View attachment 70724
> View attachment 70724
> Hmmm..... Nested fish hook?


The sushi in the background clearly shows how good they cut


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## Michi

Caleb Cox said:


> Unfortunately this is the only pic I have a blade with an effect like what I'm describing.


That is one seriously pretty knife! What is it?


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## Caleb Cox

Michi said:


> That is one seriously pretty knife! What is it?


Thanks! The blade is in ZDP-189 and is made in Japan, though I don't know by who. It's from Jantz, a knifemaking supply company. A friend had me make a handle of ironwood burl and mosaic pins to complete a gift for his brother.


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## playero

That would be a pain to sharpen


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## Michi

playero said:


> That would be a pain to sharpen


Why? The ZDP-189 I've sharpened so far wasn't that difficult. Slower than white or blue, sure. Only a little bit more tedious than SG-2. Just be patient when sharpening, and it'll work out fine.


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## daizee

Deeper-Etched Damascus can be felt by hand. The darker material etches away faster than the brighter one.

Re: nested knives: cute in a museum store, but what if you want the big one first? Or the middle one? Or don't want to whack the edges into the others replacing them? And does it have to live on the counter or in a drawer?


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## Michi

This is one of those design ideas that win awards. It really does look cool, and someone put a lot of thought into coming up with what is essentially a piece of art.

But it's a solution in search of a problem. It simply isn't practical to laboriously nest the knives inside each other every time I want to put them away. (If I don't nest them, I don't save any space and might as well use ordinary knives instead.) Of all the knife users in the world, what percentage actually _need_ this particular solution?

I've never used these knives, but I strongly suspect that they extract a price in terms of ergonomics. Those handles cannot possibly be as comfortable and utilitarian as a western or a Wa handle.

And I'm worried about that big gap in the centre of the blade. A lot of the time, it won't matter. But I can think of cutting big produce where the gap would become a real pain because food would catch on the lower edge at the top of the gap and mess up the cut or cause the knife to get stuck.

Moreover, where on earth are my index finger and thumb supposed to go on these for a pinch grip? I guess my index finger and thumb can have a cosy get-together while they enjoy the perimeter of the blade rattling around them…

I have no idea of the kind of grind, or how well these knives cut, or of the quality of the steel. In theory, they could be great. But, with a product such as this, chances are that they are mediocre at best.

Caveat emptor, I'd say.


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## VICTOR J CREAZZI

Actually I did find reference to the hollow grind on post #53.


Kippington said:


> I've added depth to the shinogi-step and turned the right-side primary bevel into more of a concave grind.


This thread is awesome! Thank you for sharing your quest.


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## VICTOR J CREAZZI

@Kippington I think somewhere in this thread you mentioned moving to 52100 because you needed a full hardening steel. Is this because of the asymmetry?


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## Kippington

I needed a deeper hardening steel to stop the blade from warping after heat-treat. Shallow hardening steels have more internal stresses which like to show up after grinding out a valley along one side.


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## Guirotin

Hi ! Ivm new to this forum, and i'm digging up this thread, but this is absolutely an awesome thread ! Congratulations on this idea and how well you managed to make it work ! 
I'll send you a private message !


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