How sharp is too sharp?

[WhiteRabbitAgain]

I was observing some FB forums and other places prior to coming here, and noted that in many sharpening circles, there is the view that grits over 400 are a waste of time. This was explained that for many kitchen purposes, the microserrations from the grit give it a greater ability to slice, and that for chopping type cutting, such as a straight razor (where I learned to sharpen) the highest grits and stropping are advantageous, but are unnecessary or even detrimental on kitchen knives.
This contradicted what I have seen on various higher end sharpeners on youtube, like Murray Carter, where he goes up over a thousand grit, works both the primary and secondary edge, and thins the blade.
I couldn't help but wonder if this is due to the quality of the steel more than the intended application, with carbon steel holding an edge better and lower quality stainless losing a sharp edge quickly, so a higher angle would keep it functional longer.

 

[timebard]

Lots of relevant opinions here: What grit do you finish your knives on?

Tldr: most folks here would agree that microserrations/toothiness is desirable for many kitchen knives, but 400 grit is way too low and is a waste of steel for routine sharpening. Finishing knives made of quality steel somewhere in the 2k - 6k range seems pretty typical, cheaper stainless steel perhaps in the 1k - 2k range.

 

[Tristan]

No such thing as too sharp.

 

[GorillaGrunt]

Depends on how much you like to sharpen and how good you are or are going to get at it. I like mine finished to a pretty high grit, 5k or better, natural finishers, etc. then after a shift I touch up, only takes a couple minutes if that and then every few uses I might have to go down to an Aoto. Haven’t needed the 1k in months.

12k might be too sharp because then it’s so slick that it doesn’t really cut slippery veg or fatty meat well; of course I still might just not be good enough with that stone yet.

 

[Marcelo Amaral]

At least 3k for the good stuff. Usually around 5-6k on naturals.
For the cheap stainless knives, 300 grit.

 

[flx]

I am exploring lower grit finishes recently, 2k sharpton pro with low pressure is a good allrounder and stays relatively sharp for a long time.

On carbon steels I used to go 6k Atagoyama or 8k Aiwatani and thats great too, but you have to touch it up a lot more often, especially when youre cutting vegetables with a skin.

 

[Wagnum]

I like a little tooth but that seems excessive even for softer steel

 

[Marcelo Amaral]

My cheap, soft steel is really cheap and i feel it can't take advantage of higher grit stones. Maybe one day i'll get a Shapton glass 500 to see if there's any improvement.

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This one, for instance, would be a 9-dollar blade today, but i remember paying around around 5-6 dollars a few years ago.

 

[MowgFace]

Really all depends on the user and cutting techniques.

I know what my low grit edges feel like on food and would prefer some amount of refinement. In my current cheap stainless progression I use a 320 followed by a 2000. Somewhere in the middle is where the edge ends up as I definitely don’t fully remove the 320 scratches with the 2000.

That being said, after using many of my friends knives I think I’d be happy to feel a 300 grit edge rather than a mm thick “edge”

 

[Se1ryu]

I was observing some FB forums and other places prior to coming here, and noted that in many sharpening circles, there is the view that grits over 400 are a waste of time. This was explained that for many kitchen purposes, the microserrations from the grit give it a greater ability to slice, and that for chopping type cutting, such as a straight razor (where I learned to sharpen) the highest grits and stropping are advantageous, but are unnecessary or even detrimental on kitchen knives.
This contradicted what I have seen on various higher end sharpeners on youtube, like Murray Carter, where he goes up over a thousand grit, works both the primary and secondary edge, and thins the blade.
I couldn't help but wonder if this is due to the quality of the steel more than the intended application, with carbon steel holding an edge better and lower quality stainless losing a sharp edge quickly, so a higher angle would keep it functional longer.

400 grit are way to coarse and left a deep scratches on the blade. I think for kitchen knives you can stop at 1000 grit is fine (minimum), and if you want more fine edge you can go up to 2000-3000 grit. 5000 and above is for single bevel polishing. It just silly if someone using 20-30,000 grit to polish a primary edge on Gyuto which only 1mm width.

But if someone just thinning their blade and wants to polish the secondary bevel which is the bigger bevel than it's a different story. depends on type of finished do you like on your secondary bevel like Kasumi/ hazy finish or semi mirror type of finished. Like that Mazaki JNS finish Gyuto, etc. CMIIW

 

[cotedupy]

As above. I'm a fully paid up member of the low-grit-n-toothy-finish fan club, but 400 is too low imo, regardless of the steel quality.

In terms of performance you can absolutely get away with a 400 grit finish on a kitchen knife. But your edge retention is likely to be shorter even if you can properly deburr it. And combine that with removing more steel each time you sharpen... there's just no point finishing that low. Even on cheaper, softer steels I finish about 800.

The problem isn't to do with 'sharpness' though. Here's a bit of fun getting HHT off a Norton Crystolon (320-ish grit and very aggressive):

 

[captaincaed]

Depends a lot on what you’re cutting, and what the task demands of your edge. My bias is “what finish level makes the job at hand easiest?” Horses for courses.

If you’re plating raw sushi, the presentation and way the surface of the fish holds the sauce will matter. Consider 8-12k depending on the steel, stone, and sharpening skill.

If you’re doing lots of raw veg prep, a 2-4k edge will give you enough teeth to cut through tough veggie skins, at about the highest refinement for making cuts easy and clean.

If you’re doing primarily butchery, 400-1k will have lots of teeth for cutting sinew, tendons and fascia - it’ll hold up a long time. If your edge is too refined, you’ll have trouble separating skin/fascia from meat, and you’ll cut through meat instead of separating wheat from chafe.

If you just want a “general purpose” edge, anything from 1-4k is great. 400 would feel a bit coarse for general use for me, but to each their own. FWIW, on the other end of things, 6-8k is a bit of a “dead zone” to me, where it’s too refined to have many teeth for veggies, and not refined enough to “fall through food” or give those super-clean presentation cuts. YMMV

If you have “softer” steel like Victorinox or Misen, going a bit coarser often helps, since those edges don’t take a higher-grit finishes as well as steels like VG-10/White/Blue/fill-in-the-blank steel taken to 60+ HRC.

 

[Benuser]

400 may feel great, but even when completely deburred, as @cotedupy rightly presupposed, which isn't that simple, it won't hold for a long time: only the top of the serrations have board contact, and as soon as they are worn, the feeling is gone. This explains the addiction to diamond rods amongst the general public.

 

[cotedupy]

400 may feel great, but even when completely deburred, as @cotedupy rightly presupposed, which isn't that simple, it won't hold for a long time: only the top of the serrations have board contact, and as soon as they are worn, the feeling is gone. This explains the addiction to diamond rods amongst the general public.

A good number of your posts over the years have helped me understand about the nuances of what’s going on with things like this!

 

[Kawa]

It also depends in how much of a hobby sharpening is to you.

As said above, a high gritt finish (5000-8000 range) can be nice, but you have to touch up a lot more. That ultimate sharp feeling wil become a slick, not-immediately-slicing-feeling very soon. In general, the worse the steel, the sooner this happens.

If your a home cook who loves sharpening, it might still work for you.

I've finished crap steel on hight gritt also (little did I know back then) and they get sharper then at lets say 1000 gritt. But I was touching up more then cutting. Still had my fun in either preparing food as sharpening with this approach.

 

[Benuser]

It also depends in how much of a hobby sharpening is to you.

As said above, a high gritt finish (5000-8000 range) can be nice, but you have to touch up a lot more. That ultimate sharp feeling wil become a slick, not-immediately-slicing-feeling very soon. In general, the worse the steel, the sooner this happens.

If your a home cook who loves sharpening, it might still work for you.

I've finished crap steel on hight gritt also (little did I know back then) and they get sharper then at lets say 1000 gritt. But I was touching up more then cutting. Still had my fun in either preparing food as sharpening with this approach.

If a high grit involves more touch-ups it's more about the steel that doesn't support a high polish because of the lack of edge stability, as in German soft stainless. With simple carbons, hard or soft, I don't see them holding a 2k edge longer than a 8k. And for touching-up a high grit is so much simpler than a coarser one.

 

[Jovidah]

There's also the issue of lower grit causing more cell damage leading to faster oxidation. Yes, a hacksaw will also go through tomatos and apples just fine, but that doesn't mean it leads to appetizing looking tomatos and apples 2 hours later.

 

[Marcelo Amaral]

400 may feel great, but even when completely deburred, as @cotedupy rightly presupposed, which isn't that simple, it won't hold for a long time: only the top of the serrations have board contact, and as soon as they are worn, the feeling is gone. This explains the addiction to diamond rods amongst the general public.

Cheap stuff's retention is bad no matter what, but i feel the retention is actually worse when higher grit (even 1000 grit) is used to sharpen. No problems deburring on higher grit stones though.

In my experience, the best way to keep more teeth longer is to do a little thinning behind the edge instead of only sharpening the edge. That holds true for good blades also when thinning them on JNS 300 before starting the progression on naturals.

 

[Desert Rat]

To acute of an angle gets sticky on my butcher block. A more obtuse angle works better for me if a knife is sticky on the board.

 

[M1k3]

I've been using a 120 grit + strop on towel edge for the past week. Works great on waxy produce!

 

[McMan]

OP, this is a topic that seams to come up again and again.
Here's a similar thread. I think there are others that are out there too.

What is sharp?

Lately I have been questioning seriously my sharpening skills. I started with a Kurosaki R2 and I learned how to get it sharp on my naniwa professional 3000. The knife not only cut well fresh out of the stones but stayed tomato skin cutting sharp for a week of home cooking at least. I was then...

www.kitchenknifeforums.com

As to 400-grit:

How sharp should I be able to get a knife on 400 grit?

So, I have a vitrified aluminium oxide 100/400 combo stone. After the 400 grit, I can get paper to slice cut paper cleanly but not push cut. Should I get it sharper before progressing to 1k?

www.kitchenknifeforums.com

TLDR, rarely will 400 be the best option, for multiple reasons (as others note above--tough to deburr well enough, won't dull into sharpness, loses steel as compared to higher grits, too toothy, etc.). 400 might work well enough on goofy stainless, where anything past 1000 is like polishing an eraser.
Use is an important consideration too. There's a big difference between cutting 6 tomatoes (home cook) and 600 tomatoes (pro). I might guess that some pros prefer a toothier edge than some home cooks. Maintenance matters, Time to sharpen, Type of product, Type of cutting board. Etc. Etc. Etc.
All this to say, there are a lot of variables. And different people will have different opinions, based on their usages habits, about what a good finishing grit is and why. There is a range. There is no definitive magic number. Regardless, 400 is too low IMO.

 

[Ruso]

Maybe they talk ANSI or FEPA which will be about 800JIS.
At 800 JIS you can get a decent edge, for sure.

 

[KingShapton]

Use is an important consideration too. There's a big difference between cutting 6 tomatoes (home cook) and 600 tomatoes (pro). I might guess that some pros prefer a toothier edge than some home cooks. Maintenance matters, Time to sharpen, Type of product, Type of cutting board. Etc. Etc. Etc.
All this to say, there are a lot of variables. And different people will have different opinions, based on their usages habits, about what a good finishing grit is and why. There is a range. There is no definitive magic number.

 

[KingShapton]

I've been using a 120 grit + strop on towel edge for the past week. Works great on waxy produce!

Venev 120?

 

[Jovidah]

I've been using a 120 grit + strop on towel edge for the past week. Works great on waxy produce!

But what grit is your towel?

 

[M1k3]

Venev 120?

Shapton Pro 🫣

But what grit is your towel?

Depends on what I've wiped up with it.

 

[Matt Jacobs]

I have had pretty good success with a Chosera 800 and strop but I vastly prefer my 2k Shapton Pro edge. Sometimes I go up to 5k on my Rikka and with good steel it is a nice edge but I think the 2k is perfect in a kitchen. On my cheep stainless I will sometimes do edge leading passes on a 400 grit to "freshen up the edge" and that works ok for a very short amount of time. No way would I be happy stopping at 400 grit on any of my daily use knives.

 

[KingShapton]

I have had pretty good success with a Chosera 800 and strop but I vastly prefer my 2k Shapton Pro edge. Sometimes I go up to 5k on my Rikka and with good steel it is a nice edge but I think the 2k is perfect in a kitchen. On my cheep stainless I will sometimes do edge leading passes on a 400 grit to "freshen up the edge" and that works ok for a very short amount of time. No way would I be happy stopping at 400 grit on any of my daily use knives.

2K is the transition between sharpening and polishing.

The Stones (not just Shapton) leave a very good all round edge depending on the skill of the user, pressure used etc.

Of course it's always a matter of personal preference, what is a good edge with bite for one person is not fine enough for another...

 

[Benuser]

I have had pretty good success with a Chosera 800 and strop but I vastly prefer my 2k Shapton Pro edge. Sometimes I go up to 5k on my Rikka and with good steel it is a nice edge but I think the 2k is perfect in a kitchen. On my cheep stainless I will sometimes do edge leading passes on a 400 grit to "freshen up the edge" and that works ok for a very short amount of time. No way would I be happy stopping at 400 grit on any of my daily use knives.

There is little difference in grit between both. Both are excellent stones. The Chosera has more versatility. If you use it as a last stone — perhaps with soft stainless — deburring on the Shapton is a bit easier.

 

[stringer]

I've been using a 120 grit + strop on towel edge for the past week. Works great on waxy produce!

Probably eats your blade height pretty quick. Or do you just go a few strokes at a time?