Do Diamond Stones Wear Out?

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harlycarly

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I have heard it said that diamonds are forever, but what about diamond sharpeners? I've got a couple of Lansky diamond stones and a few of the DMT credit card type. I've had them a while and it seems that they have become smoother in certain spots. Do this types of sharpeners wear out over time?
 
I had to replace my lansky extra course diamond stone after a lot of use. Definitely smoothed out. Was about equal to the medium diamond stone.
 
Mine seem to wear down too. I suppose the diamonds are forever but the bonding to the surface of the sharpening tools degrade over usage. Or maybe another theory of mine is the diamonds chip and load the surface over time and cannot be cleaned out. I'm not sure but they don't last forever.


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Rather than 'wearing out', more likely the diamond particles are being knocked loose from the substrate.
 
Diamond does wear, fracture, and loosen over time. Essentially, diamond stones are really fancy sandpaper. Contrary to what many will tell you, they don't last forever, nor do they maintain the same quality of cut.
 
harlycarly said:
I have heard it said that diamonds are forever, but what about diamond sharpeners? I've got a couple of Lansky diamond stones and a few of the DMT credit card type. I've had them a while and it seems that they have become smoother in certain spots. Do this types of sharpeners wear out over time?
Click to expand...

Smaller diamond hones, like Lansky's and the credit card types, have to do a lot more work per unit of surface area, if used for heavy jobs like rebevelling. If they are used as such, they'd be expected to wear faster. But with that said, they can also last quite a while (a decade or more) if they're used with the right pressure.

There's a lot to be said about the quality of the hone itself, and the strength with which the nickel substrate holds onto the diamond grit. It varies with quality. I have the Lansky hones and the DMT credit cards, as well as others from DMT, Gatco and EZE-Lap. My Lansky hones have worn faster than the DMTs, and they also seem to be much more prone to clogging, which can make them appear more worn than they actually are. Keeping the Lansky hones clean and lubricated makes a difference, to keep them from becoming clogged. Low-alloy 'soft' stainless steels will clog them very quickly, for example. A clogged diamond hone will get very slow, and the natural tendency is to press harder when they get slow. That'll wear the hone even faster.


David
 
I agree with 42. They wear, or are fractured off and the grinding material is only a few thousands. So, yes they must be treated lightly as they can be wore down. Plus, they are expensive compared to other stone types. DM
 
My first diamond hones were a set of 6" DMT diamond interrupted surface - the blue/red/green plastic base polka-dot stones. Before I had educated myself though trial and error, I tended to use the finer stones when I should have been using a coarser mesh, and to compensate I used more pressure.

As a result, my red (fine) hone has some areas where the metal substrate that the diamonds were embedded in are largely smooth and no longer abrade. So yes, I would say you can wear out a diamond hone, if you use too much pressure and end up pulling the diamonds out of the substrate.
 
I think brand plays a part when thinking about durability. My atoma plates still feel new even after many sessions of heavy use verses my DMT plate that wore down significantly after the first few uses.
 
Thanks for all the responses. It confirms my suspicions at to what was happening and also reminds me that I've had the Lansky for at least 25 years, maybe more. And yeah, I was definitely more heavy handed back in my younger days, in more ways than one. Time to replace the smooth ones.

I appreciate the replies.
 
I have used the same set of 6" DMT bench stones for 20+ years and they still work as well as when brand new. I hone dry, wiping with a soft cloth to pick up the scarf when it starts to be evident. Once in a while when they seem to be loading up I spray them with BreakFree and let them sit overnight before wiping dry. That seems to restore their cutting efficiency. I did wear down an ultra coarse DMT 4" by using excessive pressure.
 
Large diamond stones (10") didn't help me. They still wore down quickly.
 
Even with low pressure diamonds will eventually wear and fracture. They're very hard, yes, but not very tough. The particles can and do wear even with proper use.
 
I've used my DMT stones for 8+ years now in a professional setting, they all still work very well but I can tell they have dulled a bit. Not so much that it's changed the resulting edge but enough to feel they are not cutting as aggressively as when they were new.

My XXC is probably the worst, it's set the bevel on nearly every knife I have sharpened and flattened my waterstones thousands and thousands of times. Still about as fast as my new Atoma 140 though.

Diamond stones will wear out eventually but for someone sharpening their own knives it probably won't happen in their lifetime unless used improperly.
 
I wouldn't say that they wear "out". I've used DMT stones extensively for 20 years now and I still have the same diafold I had when I was in the Army. Instead of wearing out, I'd say they wear in. My old diafold (red/blue, fine/coarse) is more like extra fine/extra extra fine now! It still works, but I use it more of a finishing grit more than anything. You can't go wrong with diamonds. If you go with diamonds, DMT is the best IMO. There are polychrystalline and monochrystalline diamonds. Mono is the way to go, as poly breaks off shards more easily than the mono does. DMT is mono.

dmt-crystals.jpg
 
Most important facts stated:

Use light pressure. The matrix will lose diamonds way faster under heavy pressure.

Don't breath in diamond dust or touch your face-eyes.
 
Diamond honing stones are made by using electroless nickel plating to hold the diamond particles to the steel substrate.
This nickel plating is not as hard as diamonds, nor is it as hard as even your cheapest knife blade.
Once the raised portions of the exposed diamonds fracture, the soft nickel plating is exposed, and it can wear quickly.
Diamonds can also be torn out of the softer plating.
 
there is poly and mono diamond types, and then there is bonded and coated diamond plates.

each has different properties when using them as sharpening abrasives.

bonded diamonds are not the same as what's described in the above post.

bonded are diamonds mixed in with a resin which is applied to the stone. They work more like a traditional stone and they are less aggressive because there is less space between the diamonds.

bonded stones will be thicker as when they wear away it then wears down. where as the coated diamond stones are coated with diamonds on the top.

for coated diamond stones, you may get a 1000grit stone but it will feel more aggressive until it's worn in after some use.

bonded stones may last longer, but that's debatable because of so many variables. venev makes bonded diamond stones.
 
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+1 all the above. Some of them will last a long time but if abused will die rapidly.

Even if used carefully the abrasive will fracture and dull over time. Will still work but not as well. Ultimately they wear out, I only use mine on high Vanadium steel.
 
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