Why Use Ceramic When You Have Diamond?

[Chronovore]

Nerve issues have made regular sharpening a challenge. So I finally broke down and bought a KME. I got the deluxe kit because "why not". I knew I'd use the diamond stones for my knives in D2, 9Cr18Mov, and M390. Then I got to thinking, why wouldn't I just use the diamond stones for all my knives? It ought to save time if nothing else.

So help me out. Is there a good reason to use the ceramic stones?

 

[allenC]

From my experience...

They can be very aggressive to the softer metals and actually remove more metal than needed to sharpen a blade.
I also don't think they polish a cutting edge as nice as ceramic or Arkansas stone.

But one could definitely make do with just a diamond.

 

[Sonnydaze]

I have a nice diamond stone that I use with my Edge Pro...but I ONLY use it to reprofile the edge angle...as was said, diamond is very aggressive.
So, I use it as a rough cut only, and it does the job, but then I switch to more conventional stones to sharpen and polish.

 

[GIRLYmann]

Diamonds cuts faster, require less time or energy.
But it is rather unforgiving to careless use.
Use sparingly is key to a happy relationship
Its great for chipped edges
but i wouldn't recommend a diamond should
an alternative like ceramic is available for touch ups.

 

[Obsessed with Edges]

Nerve issues have made regular sharpening a challenge. So I finally broke down and bought a KME. I got the deluxe kit because "why not". I knew I'd use the diamond stones for my knives in D2, 9Cr18Mov, and M390. Then I got to thinking, why wouldn't I just use the diamond stones for all my knives? It ought to save time if nothing else.

So help me out. Is there a good reason to use the ceramic stones?

If you like the edges you get from using diamond, there's really no reason not to use them. Also, diamond cuts & removes metal efficiently at a lighter touch. It's about > 3X as hard as most ceramic grits, which means it'll cut as deeply with about 1/3rd of the pressure used for other grit types. Light touch is a good thing for finishing, and will also reduce pain & fatigue in your hands if you have issues with that.

As to the argument that diamond is too aggressive for simpler steels, the fix is easy. Use a finer grit of diamond for jobs on simpler steels that ordinarily might want for something coarser in other stone types. Anything from Fine (600) through EF (1200) in diamond can leave great working edges on simpler steels for which you might otherwise use a 320 - 400 stone of another grit type, like aluminum oxide or silicon carbide. For example, in small blades of mine in simple steels, like pocketknives in 1095, CV, 420HC, etc., I'd likely be using something no more coarse than 600-mesh (DMT) for those, even for reprofiling. In other stone types, I'd be finishing with something like a Fine India stone (320-360), for the same blades.

Diamond will usually leave edges cleaner (of burrs) than most ceramics will. Burring issues are most of the reason I don't use ceramics much anymore, except for very, very light touch-ups here & there.

 

[Night Rider]

From my experience...

They can be very aggressive to the softer metals and actually remove more metal than needed to sharpen a blade.
I also don't think they polish a cutting edge as nice as ceramic or Arkansas stone.

But one could definitely make do with just a diamond.

One hour with the KME and Lapping films. Nuff said

 

[Mr.Wizard]

Also, diamond cuts & removes metal efficiently at a lighter touch. It's about > 3X as hard as most ceramic grits, which means it'll cut as deeply with about 1/3rd of the pressure used for other grit types.

You may be confusing the depth of impressioning with a specific indenter on different workpieces (during hardness testing) with the depth of penetration of a specific workpiece by different indeters. So long as the indenter or abrasive grain has sufficiently greater hardness than the workpiece it will penetrate to the full depth the geometry and force (ergo pressure) allow. If the ceramic grains are blunted by e.g. vanadium carbides the point pressure and penetration depth will decrease, but not in the simple relationship you posit.

 

[Ourorboros]

If you have a range of steels and only one choice of a series of stones, sure.
But at least from a hand sharpening perspective, I don't like diamonds on simpler steels.
Most diamond stones require wear in to cut at the stated grit level.
But whatever works for you.

 

[David Martin]

If you only sharpen one knife a month then diamond will be fine. It's not they wear more, it's the material is so thin when compared to a 1/2"
thickness of many other stones. And many of the steels we sharpen do not require diamond to cut them. For me it's about economy. Not so
much about how it cuts but how it wears. DM

 

[Night Rider]

Knives of varying steals I have recently sharpened for friends and co workers. Mind you my KME stones are over a year old and I'm still working with the same box of lapping films. It took about four knives for the stones to feel broken in and I get about 8 knives finished per lapping film before I digard them. I hope this info helps someone. Good day and stay safe.

 

[wade7575]

Chronovore If you have the KME Gold Series diamond stones I found them to be more aggressive then the DMT diamond stones,as others have mentioned just don't go crazy with them and stop once a burr is formed and move onto the next stone.

If you want really good stones look at these Venev dual sided stones they are around 9 bucks each,they are 25% concentration and I have not used them I use the single sided stones mounted to an edge pro blank and mine are 100% diamond concentration.

You ask Konstantin at gritomatic if they are going to start carrying them in 100% and if they are I would jump in them for sure,the Venev stones are the best stones I have ever used and I have tried a lot of different brands,the 100% ones work great on every steel I have tried them on which is also a lot,the 100% stones although they claim give a more toothy edge it is true they do give a more toothy edge cutting performance but they also refine the edge better then any other diamond stone I have used and you also get a polished edge effect going on at the same time.

I use my Venev stones mainly on S30V S90V S110V and M390 and M4 and they really do a great job on these steels.

https://www.gritomatic.com/collecti...al-side-bonded-diamond?variant=31752609366125

 

[Diemaker]

If you only sharpen one knife a month then diamond will be fine. It's not they wear more, it's the material is so thin when compared to a 1/2"
thickness of many other stones. And many of the steels we sharpen do not require diamond to cut them. For me it's about economy. Not so
much about how it cuts but how it wears. DM

At EP the Matrix stones loose about .001" of thickness per 1000 knives sharpened, on average. The coarser stones lose a little more, the finer stones a little less, and a little more when Cody overdresses. They too can be a good value if you live long enough. How thick the abrasive layer is doesn't really indicate how long it will last.

 

[Blues]

...dumb joke removed...

 

[David Martin]

O-brother. DM

 

[Ready_AF]

The KME diamonds are great. Just go easy on them as others have said.

The real beauty of the diamond stones on the KME system in particular is they are all the same thickness as each other and the same thickness of the lapping glass. So your angle always stays exactly the same. No angle adjustment required.