Beyond CoarseMediumFine when sharpening?

[Malty Falcon]

I've used sharpening stones for many years, mostly the venerable Norton Tri-Stone, as a cook in restaurant kitchens. I now have two, one in each restaurant kitchen. After buying a couple folders with harder steels, I got a Triangle Sharpmaker, which worked great for almost every knife.

I found a cool knife with recurve blade in CPM 20CV, and thought I needed Spyderco's Gauntlet, which works great for most knives, but still not all of them. It's amazing on our German chef's knives In particular, I could get a decent edge on my Manix 2 in CPM S110V or another knife with CTS-204P, but it won't last. I've also tried the Chef's Choice device; it's in the back of a cabinet somewhere.

I just got the Manix back from an acquaintance who could sharpen it at 18 degrees out to what he said was perhaps 18,000 grit(????). It is fabulous, and I suspect the edge will last even longer than "factory-sharp". MY QUESTION- Which is more important to achieve a really sharp knife: consistently achieve whatever bevel is optimal, or sharpening/polishing out finer than 1000 grit?

My question mostly applies to EDC kind of pocket knives. But along the same lines, would sharpening a camp knife or competition chopper with finer stones or compounds do any good?

PS...
new member and loving the content, pics on BF

 

[shane45-1911]

For me, I have no need for anything beyond 600 grit.

Assuming you can sharpen at a consistent angle and keep your bevels even, that is more important than a mirror polish of your edge - to me.

In my experiences, anything higher than a 1200 grit edge quickly becomes a 600 grit edge anyway, regardless of steel type and regardless of what you are cutting.

 

[DMG]

I've used sharpening stones for many years, mostly the venerable Norton Tri-Stone, as a cook in restaurant kitchens. I now have two, one in each restaurant kitchen. After buying a couple folders with harder steels, I got a Triangle Sharpmaker, which worked great for almost every knife.

I found a cool knife with recurve blade in CPM 20CV, and thought I needed Spyderco's Gauntlet, which works great for most knives, but still not all of them. It's amazing on our German chef's knives In particular, I could get a decent edge on my Manix 2 in CPM S110V or another knife with CTS-204P, but it won't last. I've also tried the Chef's Choice device; it's in the back of a cabinet somewhere.

I just got the Manix back from an acquaintance who could sharpen it at 18 degrees out to what he said was perhaps 18,000 grit(????). It is fabulous, and I suspect the edge will last even longer than "factory-sharp". MY QUESTION- Which is more important to achieve a really sharp knife: consistently achieve whatever bevel is optimal, or sharpening/polishing out finer than 1000 grit?

My question mostly applies to EDC kind of pocket knives. But along the same lines, would sharpening a camp knife or competition chopper with finer stones or compounds do any good?

PS...
new member and loving the content, pics on BF

I can get my knives shaving sharp with the grey rods on a Sharpmaker and leave the edge toothy enough to cut well. a Polished edge looks awesome but it isn’t going to stay sharp longer and will cut some things better and some things not as well as a coarse but still sharp edge.

 

[SwissHeritageCo]

For me personally, practicality remains king.

 

[cudgee]

MY QUESTION- Which is more important to achieve a really sharp knife: consistently achieve whatever bevel is optimal

You have answered your own question. Whatever bevel you decide is best for your knife and what you will be using it for. Keep it constant.

My question mostly applies to EDC kind of pocket knives.

I only need between 600 to 1200 grit to get a really sharp EDC, just make sure you Apex on your first grit, that is the most important thing.

 

[Londinium Armoury]

I rarely go past 1000 grit / medium ceramic rods for general use knives. Wood working, shaving, kitchen knives, precision slicers. Depends on the steel type, if they are low alloy I will sometimes go very high into the thousands and strop with compound. Rarely bother doing much to high alloy tool steels and stainless, keep them at around 400+ Then just hone on ceramic rods to bring back the edge after use.

Going up to 18 thousand + grit on a manix is probably counter productive as it's probably S30V. To get the sharpest knife possible level of polish isn't the factor that's important, it's the acuteness of the steel angle. So a fine grain structure steel, which has small tight carbides, which has the lowest possible edge degree and apex will be the sharpest. Once you have the optimal sharpest possible geometry then the polish will matter. A very thin fine BTE razor will always slice better and be sharper than a thicker knife, even if the thicker BTE knife has a higher polish.
So to make your knife as sharp as possible you basically want to sharpen away as much material as possible and make it very thin BTE.
Some steels benefit from high polish and some do not.
For example putting a 0.01 compound edge on maxamet is kind of a waste of your time. Where as putting that absolute mirror edge on a Shirogami kitchen knife, that is actually very practical and encouraged, for the higher the polish the more beautiful of a cut it leaves in the presentation of the food.
Same goes for wood working tools, planers chisels etc, a fine polish makes a fine cut.
Competition choppers and beaters, as long as they are apexed crisp at any grit they should be fine, even if it's 250-300 grit.

 

[kobold]

Polshed edge for food processing and whittling. For EDC it is better to stay under 3000. Where exactly, depends on the steel, intended use, and personal preference. Even a 200 grit stone can achieve shaving sharpness.

 

[Ourorboros]

"Best" depends on the steel, what you are trying to do, and how you are trying to do it.
I don't see the point in going beyond medium then stropping for D2, ever. Maybe even just coarse then stropping.
EDC and cutting through some cord? A fine grind works fine for push cutting on a surface, but if it's hanging you'll like a coarser edge better.

 

[Obsessed with Edges]

I found a balance between two things:
(1) 'As wickedly sharp as I can possibly need for anything' and...
(2) 'How much work does it take to make it that sharp AND maintain it as such?'

I found the best balance for me is heavily slanted toward the ease of sharpening and upkeep end of the spectrum. It really doesn't take a lot of polishing of the edge to make it very, very sharp. And a very, very sharp edge produced in the coarse-to-medium end of the spectrum is also very simple to maintain and less prone to damage that stops cutting in it's tracks. I also tend to believe that, for most tasks, a toothy bite will last longer on a sharp edge, than will a super-mirror-polished high-grit edge.

So, all the above essentially means I never see a justifiable need to finish any higher than 600-1200 or so. I set my edges initially somewhere in the 225-600 range, using hones like DMTs Extra-Coarse (220) or Coarse (325), Norton India 'Fine' (360 - 400 ballpark), or DMT Fine (600). And for subsequent touching up, I often do that with a few very light passes on a medium or fine ceramic like Spyderco's M/F hones. Usually, the passes on the ceramic are very minimally applied at the lightest touch as a barely perceptible microbevel.

Most true 'sharpness' is more about cross-sectional edge geometry and apex width. That can be done at most any grit, by setting the edge geometry as acute as can be, while still being realistic and pragmatic about edge durability at thinner edge angles. For the knives I use and the tasks I use them for, that means I'm willing and happy to take my edges' geometry down to around 25° inclusive (12.5° per side), where they'll cut beautifully AND won't be too prone to excessive damage and will therefore be relatively easy to maintain in good condition.

For polished edges, I DO like a very acute polished convex on kitchen knives used for slicing/chopping veggies & such. Works great for that. And a polished convex also works very well for cutting tough material like cardboard, and more so if used on thicker blades. The polished convex is what keeps the blade's upper grind from binding in the material. Cutting gets very slick in cardboard, with the convex polished - so keep the fingers well clear of the blade.

 

[Malty Falcon]

Thanks for the explanations....polish the edge for kitchen work makes sense- and polishing not necessary for EDC knives to use on boxes, cords, and packing materials.
Got it!

 

[Diemaker]

I like my EDC for boxes finely polished, after the 5 micron stone, and the edge still lasts for months if it's Maxamet. To me, the finer the grit I use the sharper/keener I can get the edge. How long that edge holds up depends on what you are doing with it and the steel. Sure, I can get a knife "shaving" sharp with a 250 but if I look at the edge under a microscope it looks pretty ragged, as in the apex is missing, crumbled off. That apex keeps looking better and better the finer the stone I use.