# Hair splitting sharpness.



## Wei Jun Lee (Jun 18, 2019)

Hye guys. 

So I'm working as a chef, and I can get my knives up pretty sharp, but it seems to stop there. Can't seem to get it any sharoer than pretty sharp. And I'd like to get my knives up to hair splitting sharpness. Is there a way you guys so do it? I mainly use single bevel knives. I use a variety of different stones. #1000 #3000 #6000 #10000. I sharpen on these stones one a week, and normally touch up my knives on the 1000s every night after service. 

So the question is. How do you guys get your knives hair splittingly sharp?


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## JLaz (Jun 18, 2019)

Hey man,

Nice to see another fellow chef around!

Have you tried strops? When I started using strops, ive realized how big a difference it makes to have the burr completely removed. Stropping has made that easier for me.

Fyi, im just using a humble felt strop loaded with some flitz.


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## Benuser (Jun 18, 2019)

Not sure I understand. So, in your progression you go up to 10k, but when touching up you use a 1k, is that correct?


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## Wei Jun Lee (Jun 18, 2019)

Mistake post


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## Wei Jun Lee (Jun 18, 2019)

JLaz said:


> Hey man,
> 
> Nice to see another fellow chef around!
> 
> ...


 Yeah I do. Haha it helps definitely. But I still can't get my knives to split hair sharp. So just wondering how do ppl get their knives that sharp. Stones? Sharpening techniques?


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## Wei Jun Lee (Jun 18, 2019)

Benuser said:


> Not sure I understand. So, in your progression you go up to 10k, but when touching up you use a 1k, is that correct?


 Yes yes. That's right.


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## J.C (Jun 18, 2019)

IMO, if you sharpen up to 10k grit properly. Instead of touching up in 1k, you can touch up single bevel knives with 4-5k stone (splash n go). Meanwhile, with double bevel knives, invest on a stropping block loaded with compound.


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## osakajoe (Jun 18, 2019)

What are you cutting with your knives or what is your job? Since you say you only use single bevels are you a sushi chef or traditional Japanese cooking? 
Why do you feel your knives are not as sharp as they can get?

Answer these questions and maybe we can way in more.


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## dough (Jun 18, 2019)

Well it’s hard to say but my belief is it’s a technique issue bc I rarely strop or take my kitchen knives to 10k. I tend to just polish in those grits so things look pretty.


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## Wei Jun Lee (Jun 18, 2019)

osakajoe said:


> What are you cutting with your knives or what is your job? Since you say you only use single bevels are you a sushi chef or traditional Japanese cooking?
> Why do you feel your knives are not as sharp as they can get?
> 
> Answer these questions and maybe we can way in more.



I'm a chef working in a Japanese restaurant for the past few years. Currently working in a Japanese kaiseki restaurant. Have worked as a sushi chef as well before. 

Im asking because I want to be able to sharpen my knives to a razor sharp level. Hence splitting hairs. Its adequate now as is. But I feel I can always improve, and I have that misconception that the type of stones(naturals vs synthetic) have a lot to do with how sharp you can sharpen your knives to.


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## MrHiggins (Jun 18, 2019)

A suggestion is to use minimal (and I mean MINIMAL) pressure when you're in the end-stages of your sharpening progression. I feel like once I started concentrating on light pressure, my edges became much sharper and less likely to retain an unwanted burr.


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## Wei Jun Lee (Jun 18, 2019)

dough said:


> Well it’s hard to say but my belief is it’s a technique issue bc I rarely strop or take my kitchen knives to 10k. I tend to just polish in those grits so things look pretty.


 
I believe it has something to do with my technique as well. But I usually follow the bevel when sharpening my single bevels.


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## Wei Jun Lee (Jun 18, 2019)

MrHiggins said:


> A suggestion is to use minimal (and I mean MINIMAL) pressure when you're in the end-stages of your sharpening progression. I feel like once I started concentrating on light pressure, my edges became much sharper and less likely to retain an unwanted burr.




Owhhh. I still press pretty hard on the higher level grits . Although I do finish my knives on a strop. I'll keep that suggestion in mind. Thank you!


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## CoteRotie (Jun 18, 2019)

There's also DM's double sharpening technique.. There's a thread around here somewhere I'll dig out later if no one beats me to it.


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## CoteRotie (Jun 18, 2019)

Here's the link to the excellent thread started by Michi:

https://www.kitchenknifeforums.com/threads/all-about-burrs….41570/


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## Nemo (Jun 18, 2019)

IME, the biggest impediment to getting hair splitting sharpness is failing to propperly deburr.

Pressure control is important to this. On the coarsest stone in your progression (whether that stone be 400 or 10K for that particular sharpening or touch up), start with fairly high pressure until you get a burr. Then continue ON THE SAME STONE with gradually reducing pressure in 3-4 steps, producing a burr on each occasion. The last time should be with very light pressure, barely the weight of the knife. You will probably feel pieces of burr break off in this process (you can feel them and sometimes see them in the swarf). I then deburr with a sideways stroke along the edge of the knife then pull the edge GENTLY through a cork.

Continue on to the next stones in your progression, but only use very light pressure on each stone, deburring after each stone.

I found the Dave Martell technique of repeating the sharpening on the last 1-2 stones to improve my results as well.

For highly alloyed steels, especiallly if there are tungsten carbides, stropping on a diamond loaded medium (I use balsa with 0.5 um diamond) is helpful in deburring. I often do this for simple steels as well. Diamond pastes are cheaply available at lapidiary suppliers. Even more cheaply (in terms of cost and quality- but still do the job) on the internets.

Do you flatten and champfer your stones regularly? A flat stone is much easier to sharpen on. I flatten for each sharpening session (maybe 1-5 knives).

Also, depending on what you are cutting, 10k is a pretty high polish. It makes sense for slicing fish with a yabnagiba. Not so much for a gyuto.

+1 on the deburring thread started by @Michi.


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## Wei Jun Lee (Jun 18, 2019)

Nemo said:


> IME, the biggest impediment to getting hair splitting sharpness is failing to propperly deburr.
> 
> Pressure control is important to this. On the coarsest stone in your progression (whether that stone be 400 or 10K for that particular sharpening or touch up), start with fairly high pressure until you get a burr. Then continue ON THE SAME STONE with gradually reducing pressure in 3-4 steps, producing a burr on each occasion. The last time should be with very light pressure, barely the weight of the knife. You will probably feel pieces of burr break off in this process (you can feel them and sometimes see them in the swarf). I then deburr with a sideways stroke along the edge of the knife then pull the edge GENTLY through a cork.
> 
> ...


 

Yes I mainly use a Yanagiba at work. The knives I mainly use at work is a 300mm Yanagiba, a 180mm Yanagiba, mukimono and a deba. I do have a gyuto but that mainly stays in my kniferoll. 

Thank you for the masterful reply. I'll keep an eye out when deburrin to see it get done properly. I never knew about the light pressure on higher grits.


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## Wei Jun Lee (Jun 18, 2019)

CoteRotie said:


> There's also DM's double sharpening technique.. There's a thread around here somewhere I'll dig out later if no one beats me to it.



Thanks for sharing the thread!!


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## Keith Sinclair (Jun 19, 2019)

I would micro bevel my Deba. Yanagiba no micro so the edge was extremely sharp going to a 8K stone. With no micro the edge is more fragile but only used it for sashimi & sushi topping. Deburring the hollow ground backside of a single bevel is a light touch. You don't want pressure or too much repetition on backside you can wear it down and lose the effectiveness of the hollow grind.


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## Kai Wang (Jun 20, 2019)

Check this out. Power of natural stone 
https://www.instagram.com/p/BtO9L3yH7_Q/?igshid=1n8fgosm19hze


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## CoteRotie (Jun 20, 2019)

Kai Wang said:


> Check this out. Power of natural stone
> https://www.instagram.com/p/BtO9L3yH7_Q/?igshid=1n8fgosm19hze


Hey, Kai, which JNAT did you use for finishing? And what's that Nagura in the final photo? You're not by any chance the same Kai Wang who used to live in the Bay Area are you?


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## Kai Wang (Jun 20, 2019)

Hi Cote, 
I used Atagoyama Iromon stone, combination Mikawa Tenjyou Nagura to finish the knife. 
And not, I haven’t been in Bay Area yet. 
I just started to collect natural stones. They are very powerful. Very sharp


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## CoteRotie (Jun 20, 2019)

Kai Wang said:


> Hi Cote,
> I used Atagoyama Iromon stone, combination Mikawa Tenjyou Nagura to finish the knife.
> And not, I haven’t been in Bay Area yet.
> I just started to collect natural stones. They are very powerful. Very sharp



Ah, OK, I knew someone who lived here with the same name who went back to China to open a restaurant.


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## pennman (Jun 21, 2019)

You mean this sharp? Sharpened on 1000/3000 combo stone. Stropped on cardboard. 


https://www.instagram.com/p/BZjihJBHLms/?igshid=12gox7i9nllep


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## Benuser (Jun 23, 2019)

Wei Jun Lee said:


> Yes yes. That's right.


I'm quite aware this isn't the subject of this thread, but I feel free to react, if you don't mind. 
I use the finest stone to start touching up between full sharpenings. If I don't get a smooth feeling with one or two edge trailing strokes, no insisting, but go to the next coarser one. And again, if that doesn't work, to the next.
I want to make sure to abrade the fatigued steel, i.e. that has failed, without wasting material by going back every time to a relatively coarse one. In this way, I can postpone a full sharpening, involving some thinning with a medium-coarse stone.


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## Ivan Hersh (Jun 24, 2019)

Need to know what type of knife it's grind and what type of steel is used in the knife.


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## Wei Jun Lee (Jun 24, 2019)

Ivan Hersh said:


> Need to know what type of knife it's grind and what type of steel is used in the knife.


I mainly use single bevel knives. Most of my knives are white 1/2. Couple of ginsan as well!


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## rick alen (Jun 24, 2019)

pennman said:


> You mean this sharp? Sharpened on 1000/3000 combo stone. Stropped on cardboard.
> 
> 
> https://www.instagram.com/p/BZjihJBHLms/?igshid=12gox7i9nllep



You're cheating using a flat surface backing. The real test is trying that with hair partially backed up by thumb or finger or, more impressive, free hanging hair.

Stropping on a 6K stone with any half decent carbon steel should come very close to hanging-hair sharp.

Try sharpening to a very shallow angle, the strop on your 10K same angle, them raise the angle just a bit and finish strop a few strokes. That should get you hanging-hair sharp. Of course that sharp will disappear immediately if you hit the board with it.


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## The Edge (Jun 25, 2019)

Hair is not a qualitative measure to determine sharpness. Pick something else to judge sharpness off of, so we can truly figure out what you're looking for. My hair, for instance, is like peach fuzz, and even straight razors have difficulty taking it off. 

Otherwise, burr removal is key, and either reducing wobble in the hand, or keeping a consistent angle is next. Heavy pressure is only used on the first stone, and then subsequent stones should be super light pressure, while making sure the burr is flipped and then removed.

After all of that, knives are limited by how thin they are behind the edge.

Burrs are the most annoying part of sharpening, and even an experienced sharpener should double check to make sure the entire edge is flipped before moving to the next step. There's nothing worse than going to the last stone, only to realize that you need to take step back, and redo your own work.


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## Michi (Jun 25, 2019)

The quest for super-sharpness is a challenge in its own right. As a sport, sure thing, I can see why that is fun. But, in practice, for kitchen knives, it is largely pointless, in my opinion. Beyond some level of sharpness, the first board contact will turn the edge from super sharp to merely very sharp.

To me, the test is whether I can fall through a tomato with essentially no resistance. If so, the knife is sharp enough.


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## Benuser (Jun 25, 2019)

For both sharpness and edge retention, burr removal is essential. To verify, glide with your nail along the edge in both directions, on both sides. I cut through the finest cigarette paper. If it goes smoothly and silently, it's OK.


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## rick alen (Jun 25, 2019)

Well super-sharp is needed when you want very thin fine slices of something, whether it's hard salami to garlic, and putting that shiny look on sliced fish. Other than that, yes, just holding "mere sharp" is all that is important. PM steels are best for that, and carbons that come back with just a couple strops on fine stone.

Yeh thorough burr removal. Dealing with mostly PM steels these days there is not really any burr to think much about, but I was reminded of the little pest when putting and edge on a beat up folder of 154-CM. Thought it was all set, cut some paper and POOF, big ass burr curled up along the entire edge. That one surprisingly disappeared with little effort from there though and was then able to strop to final finish.


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## Benuser (Jun 25, 2019)

With the simplest carbons you may revive an edge by stropping on almost anything: leather, paper, cardboard, denim, whatever.


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## Huntdad (Jun 25, 2019)

pennman said:


> You mean this sharp? Sharpened on 1000/3000 combo stone. Stropped on cardboard.
> 
> 
> https://www.instagram.com/p/BZjihJBHLms/?igshid=12gox7i9nllep


WOW!


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## rick alen (Jun 25, 2019)

Huntdad said:


> WOW!



See post #28


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## Carl Kotte (Jun 26, 2019)

rick alen said:


> See post #28



Seriously, did you just refer back to your initial slander? Not cool!


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## Kippington (Jun 26, 2019)

I don't remember why I hit the knife at the end of the last one - it was 7 years ago...

Anyway, this is what I was doing before I started learning about blade geometry (then knife making in general). I can still get knives to this level of sharpness, but honestly I think it's kind of a waste of time. If the knife goes through tomato skin easily, it's good enough for me.

As for how it's done, hand sharpening on fine stones (or in some cases sandpaper) then stropping on something with a hard backing and some kind of polishing compound. Doesn't have to be expensive or fancy. I tend to use cardboard and metal polish from the store nowadays.


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## rick alen (Jun 26, 2019)

Yup, that's hangin'hair sharp! Metal polish and paper taped to glass, I suppose it doesn't get much cheaper than that.

This article most have probably read by now, has some very valuable information, and why PM steels high in vanadium carbides really benefit from diamond abrasives. https://www.kitchenknifeforums.com/threads/all-about-burrs….41570/


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## Ivan Hersh (Jun 28, 2019)

Really new to sharping Chef and cooking type knives, but after getting into Japanese water stones and Japanese type sharping, i have found there is a time to stop and to me it's when the knife is sharp enough to cut the material i wish to cut.
So today i can get my stones setup do the needed sharping and quit, also i found i have many stones i really don't need or will use.


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## Benuser (Jun 29, 2019)

Ivan Hersh said:


> Really new to sharping Chef and cooking type knives, but after getting into Japanese water stones and Japanese type sharping, i have found there is a time to stop and to me it's when the knife is sharp enough to cut the material i wish to cut.
> So today i can get my stones setup do the needed sharping and quit, also i found i have many stones i really don't need or will use.


Excellent if you have already found an efficient sharpening procedure, but your conclusion about stones you won't need or use is a bit hasty. You might find out that different combinations of stone are very useful with other steel types or other results you may aim for — more or less toothy, better deburring, more suited for some specific cutting technique, offering a better edge retention when used on some boards you haven't chosen, etc.


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## Michi (Jun 29, 2019)

Just my personal opinion…

Assuming you don't need to sharpen stuff that's really blunt or repair chips, there is no need for a coarse stone. Meaning that two stones are plenty sufficient: 1000 + 3000, or 1000 + 5000. Take your pick…

You can get a knife screaming sharp on a 3000 or 5000 if you strop afterwards on newspaper, cardboard, leather, or pretty much anything else that's handy, such as linen or denim.

If you need to sharpen _really_ blunt knives or repair chips, a 320 is useful. Otherwise, there is absolutely no need for it. I used mine for a repair once, and now it's sitting unused in its box…


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## Benuser (Jun 29, 2019)

I find coarser stones useful for thinning, small repairs (tip, fingerguard) and with some steels as AS you get a better end result in terms of edge stability if you started with a medium-coarse. No big steel removal or pressure, just a few light strokes.


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## Michi (Jun 29, 2019)

Michi said:


> Meaning that two stones are plenty sufficient: 1000 + 3000, or 1000 + 5000.


Forgot to mention: if all you are sharpening are soft European steels (Wüsthof, Sabatier, Opinel, Zwilling, etc.), you only need a single 1000-grit stone. The 3000 or 5000 are a waste of time on those knives. (You'll get them sharper with higher grits, but only momentarily. After the first few cuts, they are back to where they were after the 1000 stone. The steel is simply too soft to hold a very fine apex.)


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## Ivan Hersh (Jun 29, 2019)

Michi said:


> Just my personal opinion…
> 
> Assuming you don't need to sharpen stuff that's really blunt or repair chips, there is no need for a coarse stone. Meaning that two stones are plenty sufficient: 1000 + 3000, or 1000 + 5000. Take your pick…
> 
> ...


In the short time i have been working with the Japanese water stones, i feel skipping the 1000 grit and making the 2000 grit the best stone to use if blade is not really damaged or dull from use.


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## Benuser (Jun 29, 2019)

Michi said:


> Forgot to mention: if all you are sharpening are soft European steels (Wüsthof, Sabatier, Opinel, Zwilling, etc.), you only need a single 1000-grit stone. The 3000 or 5000 are a waste of time on those knives. (You'll get them sharper with higher grits, but only momentarily. After the first few cuts, they are back to where they were after the 1000 stone. The steel is simply too soft to hold a very fine apex.)


You mean soft _stainless_, I guess. A lot of makers have switched to harder stainless, with a finer grain. Those, like
European carbons, soft or less soft, benefit from refinement.


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## Michi (Jun 29, 2019)

Yes, I meant the stock-standard X50 Cr MoV 15 that is used by a lot of knife makers. Harder steels will benefit from a 3000 or 5000 grit stone.

Out of curiosity, which makers have changed to harder steels? I'm aware of Zwilling offering the Kramer carbon, and Wüsthof did a limited edition carbon steel knife maybe a year or two ago; who else does harder steels these days?


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## Sharpchef (Jun 29, 2019)

Michi said:


> Yes, I meant the stock-standard X50 Cr MoV 15 that is used by a lot of knife makers. Harder steels will benefit from a 3000 or 5000 grit stone.
> 
> Out of curiosity, which makers have changed to harder steels? I'm aware of Zwilling offering the Kramer carbon, and Wüsthof did a limited edition carbon steel knife maybe a year or two ago; who else does harder steels these days?



Herder with the K-Series, they use 1.2519 Toolsteel (with HRC 60+)... It`s comparable to Aogami 2. 

Greets Sebastian.


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## Sharpchef (Jun 29, 2019)

Zwilling also using AEBL in their Diplome Series...

Greets Sebastian.


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## Benuser (Jun 29, 2019)

Opinel uses 12C27M for the pocket lines and some kitchen knives. K-Sabatier has a 200 series from 14C28N. Zwilling the FC-61 'proprietary', I believe it's AEB-L.
As for carbons:
Robert Herder has carbon series, up to 60Rc. K-Sabatier and Thiers-issard.fr still make soft C75. 
Pallarès Solsona uses C60 at its max, 60Rc.


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## Michi (Jun 29, 2019)

Ivan Hersh said:


> In the short time i have been working with the Japanese water stones, i feel skipping the 1000 grit and making the 2000 grit the best stone to use if blade is not really damaged or dull from use.


I have no doubt that this works. Myself, I use a 3000-grit stone for touching up, when a knife starts to not cut quite as well, but isn't actually blunt yet. Works fine for me, and I'm sure that a 2000-grit stone will do pretty much the same thing.

A lot of people seem to obsess about progressions, multiple stones, finishing a kitchen knife on a 20000-grit stone, and so on. To me, that's overkill. Knives are really simple devices. (No moving parts, for starters…) It's easy to overthink things and to believe that, "with just that extra stone, I can get that extra-special edge." When, really, when it comes down to it, I can make a tin can cut like a scalpel (at least for a little while) with nothing but a 1000-grit stone and a pair of old jeans (and some sharpening skill).

Kitchen knives are not razor blades. They are (ab)used all the time, compared to the coddled existence of a cut-throat razor. ("What, you expect me to put with up getting rammed into a slab of wood after having gone through no less than a _whole_ potato?!")

Kitchen knives are like axes; razors are like surgeon's scalpels. I wouldn't use an axe to shave with, just as I wouldn't use a scalpel to fell a tree. So why would I sharpen the axe with a 20,000-grit Suehiro (or the scalpel with a round file)?

It just doesn't make sense to me to go above 5000 for a kitchen knife.


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## Benuser (Jun 29, 2019)

@Michi But as for the standard Krupp 4116 you're absolutely right. Has to do with big carbides in a weak matrix. Any polishing will weaken it a bit more and lead to edge instability.


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## Michi (Jun 29, 2019)

Thanks for all the heads-ups on harder European knives! Looks like these guys are finally realising that, just maybe, there may be something to be learned from the way the Japanese do things…


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## Sharpchef (Jun 29, 2019)

Michi said:


> Thanks for all the heads-ups on harder European knives! Looks like these guys are finally realising that, just maybe, there may be something to be learned from the way the Japanese do things…



No that is not right.... With a good reason they do it like they do... The only problem within the manufacturing of classic german chef knifes ist the much too thick grinds on knifes that could actually see hard vegetables... You can touch up german 1.4116 steel with a 1k stone and hold it for months with a good F.Dick Steel. This ist not possible with Japanese ones. 

Greets Sebastian.


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## Benuser (Jun 29, 2019)

Don't forget the very common rock chopping no hard, thin edge would survive.


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## Michi (Jun 29, 2019)

Sharpchef said:


> You can touch up german 1.4116 steel with a 1k stone and hold it for months with a good F.Dick Steel. This ist not possible with Japanese ones.





Benuser said:


> Don't forget the very common rock chopping no hard, thin edge would survive.


Agree. The remark I made was a bit flippant, my apologies. I have a whole bunch of Wüsthof knives myself, and they have their purpose. As you say, keeping them sharp is a lot less trouble than with harder steels.

Still, IMO, Wüsthof at least did something really silly when they changed to a 14º edge from the previous 20º back in 2010 or so. I don't think the steel can take that acute an angle very well, and edge retention suffers a lot. This seems to have been purely a response to increasing competition from Japanese knives.


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## rick alen (Jun 30, 2019)

Yeh, the Ikon's steel is hard enough to take an acute edge, but it doesn't have the internal structure/strength to hold it together against board contact. Fatigues very quickly and when you resharpen there is a whole lot of metal needs removing to get a decent edge back.


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## Knife2meatu (Jun 30, 2019)

Michi said:


> Forgot to mention: if all you are sharpening are soft European steels (Wüsthof, Sabatier, Opinel, Zwilling, etc.), you only need a single 1000-grit stone. The 3000 or 5000 are a waste of time on those knives. (You'll get them sharper with higher grits, but only momentarily. After the first few cuts, they are back to where they were after the 1000 stone. The steel is simply too soft to hold a very fine apex.)



I know this gets said a lot, and I am loath to fly in the face of well-established common wisdom, but it nevertheless seems to me that there can be a noticeable difference between 1k and 8k edges on such steels, even after some significant amount of use -- assuming the angle is obtuse enough to prevent the edge rolling, and the work isn't in abrasive matter.

That's the impression I've gotten once in a while, anyway -- my sharpening is still irregular enough that most of my observations are more like anecdotes recounting happy little accidents than reproducible, controlled experiments.


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## Michi (Jun 30, 2019)

Knife2meatu said:


> I know this gets said a lot, and I am loath to fly in the face of well-established common wisdom, but it nevertheless seems to me that there can be a noticeable difference between 1k and 8k edges on such steels, even after some significant amount of use -- assuming the angle is obtuse enough to prevent the edge rolling, and the work isn't in abrasive matter.


Each to his own. What's important is that _you_ are happy with your edge, not me 

I just resharpened two Wüsthofs. I finished one of them on a 1000-grit stone, and the second one got the 1000 plus 3000 treatment. I stropped both knives on chromium oxide and leather afterwards.

As best as I can tell, there is no noticeable difference between them. They are both very sharp. I also compared them to a freshly-sharpened blue #2, also finished on a 3000 stone and the two strops. The blue #2 is marginally sharper and smoother, but not really so much so that I'd notice it. (I can tell when cutting thin paper, but not when cutting tomatoes.)

To me, it's not a matter of whether the 8k edge will be sharper. Expect it will be, just a little. But what's the point? After the first two carrots, that 8000 edge will look much like the 1000 one, especially with steel that's at 57–58 hardness.

I use my knives for cooking, not surgery


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## Benuser (Jun 30, 2019)

Not so sure that Krupp's 4116 can actually take that acute edge. The last brand new ones by Wüsthof (from their Le Cordon Bleu series) in my hands at least did not and had OOTB the most spectacular wire edge I've ever seen. And prominent shoulders. 
The whole idea of getting the sharpening automated and putting a pure V-edge on it is inspired by the aim of cost reduction.


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## Knife2meatu (Jun 30, 2019)

Michi said:


> Each to his own. What's important is that _you_ are happy with your edge, not me
> 
> I just resharpened two Wüsthofs. I finished one of them on a 1000-grit stone, and the second one got the 1000 plus 3000 treatment. I stropped both knives on chromium oxide and leather afterwards.
> 
> ...



Isn't chromium oxide a sub-micron grit? This would make it substantially finer than JIS 8k stones, and more likely to cause slippery edges, or so it seems to me. Besides, I find it easier to keep a keen apex with a stone than a strop, but to each their own, I suppose.

My point however, was precisely that if the edge angle is sufficiently obtuse to hold, the 8k edge will not be reduced to looking like a 1k one, after 2 carrots. In fact, I'm not certain what mechanism precisely it is which would cause this transformation -- carrots aren't abrading steel -- albeit 57 HRC steel; and I'm not certain how having shallower striations at the apex weakens the edge with regards to board contact, rather than strengthen it. Carbide tear-out, maybe?


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## rick alen (Jun 30, 2019)

I typically say sharpen to an accute angle, then micro-bevel to suite the steel and application. But I think you have to temper this philosophy when dealing with steels like Krupp, it just needs a thicker edge.


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## Michi (Jun 30, 2019)

Knife2meatu said:


> Isn't chromium oxide a sub-micron grit? This would make it substantially finer than JIS 8k stones, and more likely to cause slippery edges, or so it seems to me.


Yes. I think it's somewhere around 14,000 grit equivalent.



Knife2meatu said:


> and I'm not certain how having shallower striations at the apex weakens the edge with regards to board contact, rather than strengthen it. Carbide tear-out, maybe?


I have no idea what actually happens at the apex. I suspect that it just ends up getting rounded off from board contact, possibly by rolling a little, or by bits of carbides flaking off.

What I've noticed is that all my Wüsthofs seem to settle in to the same sharpness in short order, no matter whether I finish them on a 1000-grit stone or a 5000-grit stone. Seeing that it doesn't seem to make any real difference, I've stopped taking them beyond 1000.


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## gman (Jul 1, 2019)

i'm another disbeliever in the theory that higher grit edges don't last as long on any given steel (softer or harder). if anything, they should be stronger than a lower grit edge, because the edge will have smaller valleys between peaks, meaning less chance for the peaks to get torn off.

the important thing to remember when sharpening a softer steels is to use a more obtuse angle, which is easier said than done if you've developed muscle memory from sharpening a lot of harder steels at very acute angles. this is where micro bevels can really come to the rescue.


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## kannamaster (Jul 1, 2019)

Sharpness is a very subjective thing and practical sharpness as compared to ultimate sharpness can not be defined without taking many factors into consideration. And in a work context you have to ask is a sharper edge actually a better edge than a slightly less sharp edge that is much easier to maintain and achieve? Most of the time we think of a more acute angled edge as being more sharp but if taken to the extreme you could creat an edge that was sharp for a very short time and would then start to break down after a few stokes and is that really useful?
I don’t find splitting a hair to be a practical sharpening goal and I would suggest that you measure sharpness by what you plan to cut with the knife. If that is fish then you should - imo - be looking to creat an edge that cuts fish with control, minimal effort, leaves a beautiful surface, is reasonably durable and is easy to recreate and maintain.
In other words you can not define sharpness outside of a set of goals for the tool you are using, the materials you will be cutting, and ratio of time and effort it takes to maintain an edge vs. the time that edge can be used. Would you spend 15 mins to sharpen a knife that would need to be resharpened after 5 mins of use?
Many people have mentioned light pressure in the final stage of sharpening and the importance of careful burr removal but what is also important is that your final burrs need to be the smallest possible burrs you can make. You must learn to create and recognize a burr along the full length of your blade that is so small that you are almost not sure it exists. Anything bigger will usually break off while you are removing the burr and you won’t know it - but your edges will show inconsistent durability. I recommend removing your final burrs by using only forward strokes at a skew angle and lifting in between strokes rather than the normal back and forth sharpening motion. This helps to more carefully “cut off” the burr instead of bending it forward and backward, breaking it off, and leaving behind a jagged edge. I’d also recommend starting with freshly flattened stones and using a nagura stone or even rubbing two finish stones together to help create mud on your finish stones before the final sharpening stage. Think of the mud as a sharpening paste and try to float your blade on top of the mud when you remove the burr. When you get to the finish stone start with the back side or flat side down first - while the stone is still as flat as possible - and polish the flat side until it is completely shiny and flat out to the edge. Starting on the flat side will also make it easier to feel any burr you create when working the bevel side. Next sharpen on the bevel side and focus on the wrought iron or soft steel of the bevel at first. You should be able to do this without making a burr while you will notice the color of the mud darkening and thickening and the bevel becoming polished. Control the consistency of the mud with a few drops of water at a time but don’t rinse the mud off the finish stone. When you are nearly done allow the mud to dry a bit and thicken and raise the sharpening angle a few degrees and use very light pressure and slow strokes until you create a shallow micro-bevel and very small burr. You’ll need to rinse the blade with water in order to carefully feel for a properly small burr. Carefully remove the burr with slow forward-only strokes. Repeat once or twice until you get a really small uniform burr, followed by a flawless burr removal. Stropping will usually not be needed but some of the modern steels especially benefit from a stropping.


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## wilburh (Jul 4, 2019)

Some folks like to sharpen and some like to cut. There's a happy medium there somewhere but you just have to find that for yourself as it varies. I'm certain that the matter could be shown by a bell curve. I'm on said curve really close to Michi but possibly not as good at sharpening. In fact, I've got a couple of knives that need sharpening right now and I think I'm gonna do it...right now!


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