Atoma vs DMT Diamond stones.

Jbrown250

Jbrown250

Platinum Member
Joined
Sep 3, 2022
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Hey everyone, looking for feedback on the two brands of stones! I own a atoma 140 for flattening my stones but would like to build up a set of diamond stones for sharpening.

I see a lot of dmt recommendations on here but have been happy with the atoma (mind you I just use it for flattening but the quality is great). So just looking for feedback from people who have used both or either.

Bonus question, are diamond stones to aggressive for softer steels like chefs knives etc, or do you just need fewer passes and a finer stone?

Thanks,

Joel
 
I haven't used DMT, but I think any of the more common trusted brands are all good. I have got the Atoma 140 and 400 and they seem to be top quality. Also have the Ezelap 250/600 grit coarse/fine and again no complaints. I would imagine DMT to be up there as well, although anecdotally I have heard the odd complaint from people who have used DMT and Ezelap, not so much Atoma. I've used the Atoma's mainly for flattening but have thinned and done repairs with the 140 and it's still going strong.

I think you will get different opinions from different people. DMT seem to be pretty popular on bladeforums.

As to using them for softer steels, generally I avoid it. I have read about softer steels causing excessive wear on diamond plates, don't know how true it is but made some sense. Something about the softer steels pulling the diamonds out of the plate vs harder steels abrading at a shallower level and being a bit less likely to cause pull-out. Also if you have regular stones, why not use them for the more basic steels? Either way, I would repeat the advise you hear about light pressure and letting the diamonds do the work. IME, that will prolong the life of diamond plates. The first coarse Ezelap plate I had years ago wore out pretty quick because I was using too much pressure before I knew better.

Atoma's generally are a bit more expensive but the plates tend to be bigger which is nice and don't seem to have too many people complaining about them. DMT, Ezelap, Ultrasharp etc. all seem to be pretty good as well.
 
Don't know anything about the Atoma, but I do have a DMT 10" double-sided Dia-Sharp (325 and 600 mesh/grit) and love it. Also have 8" DMT plates in 220 and 1200. No complaints -- they work great.

Never heard that softer steels will "pull off" the diamonds, but I do generally use other stones (Norton India and Crystolon combo stones) for softer steels rather than my diamond plates, for two reasons: First, I figure I'll "save" my diamond plates for the harder steels since the AlOx and SiC stones reportedly don't work as well for high-carbide steels (if at all); and second, because you can "bear down" on the combo stones to cut more steel faster if you want, but you shouldn't really "bear down" on a diamond plate, since (I've heard) doing so will crush/break off the diamonds and thereby wear out the plate faster, or at least make the effective "grit size" smaller.

(I also have a cheaper 400/1000 no-name diamond plate from the big internet retailer that also works well, and I sometimes use that on softer steels without worry, since if it wears out in 10 or 15 years, I figure I'll have gotten my $15 or $20 out of it... The only caveat I've heard about that cheaper diamond plate is that the mfgr didn't really grade the diamond grit as well as some other mfgrs do, and there are scattered "big" diamonds on the 1000-grit side that will make big scratches in your bevel. Don't know whether that's true, but I pass it along FWIW.)
 
Just got the Atoma 400 and 1200 for the worksharp. I haven’t used enough to give a good review. I know they will break in, but initially they are aggressive. I plan to use the 400 then 1200 then strop and call it good. Unless the edge really needs to re beveled.

For the softer steels I will be using something different like shaptons.

Good luck with your choice.
 
Re: using diamond plates on softer steels...

Not much to worry about there, if you keep pressure light. The pulling out of diamond grit from the plate is all about too much pressure used and less about the type of steel you're grinding. Diamond cuts simple steels almost literally like butter (actually has a buttery feel to the feedback with some simple steels). Don't have have to lean into it at all, to remove steel from the blade. One thing that also helps is to lubricate the plate while you're sharpening softer steels. Some soft stainless steels will leave swarf that clings tenaciously to the surface of the diamond hone in an almost galling-like fashion. If the hone is dry when this happens, it leaves the surface of the grit feeling very slick and grinding comes to a virtual standstill. The natural temptation is then to lean into it more heavily to keep grinding. That's where some damage might be done to the hone. And a dry hone with all that clingy swarf stuck to it takes a lot more scrubbing to get it unclogged. Lubricating with a very light film of oil (mineral oil) works very well to minimize that and it makes the hones very easy to keep clean and unclogged, and cutting aggressively. The oil keeps the swarf from sticking to the grit, so it won't clog as you work.

Also want to tailor your choice of grit to the steel you're sharpening. A very coarse diamond hone will leave a very ragged edge on soft steels. So, in the finishing stages, use a finer diamond hone than you might otherwise choose with a different abrasive type (AlOx, natural stones, etc.). Even if the diamond grit is rated the same as something in AlOx, the diamond will still cut much more deeply and leave a coarser scratch pattern. With very light pressure used in finishing, that coarser edge can still be a great thing for certain types of cutting. For example, I've really liked the edges produced by DMT's Coarse or Fine hones on simple kitchen blades like Victorinox's paring knives, finishing with a featherlight touch. Just be aware that it will be coarser for a given grit rating. Something like an EF DMT (1200) will produce a similar toothy bite as a Fine India (~ 400 or so), for example. I've liked DMT's hones for finishing, in particular. They seem to leave a much cleaner edge in the finishing stages that don't need much burr cleanup as compared to other diamond hones I've used, like EZE-Lap, which is still pretty good, but might take some extra work to clean up the edges.

I have no experience with Atoma, so I can't offer anything there. But they do have a good reputation, based on what I've read here on the forum.
 
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I've got full sets of Atoma, Ultra Sharp, and DMT bench stones, and until recently I would have recommended buying whichever is on sale. They have all performed very well for me in the past.

I recently purchased the 10x4" DMT stones in coarse, fine, and extra fine. These stones required a very long, very deep break-in process, much different from DMT's I've purchased previously. I finally got them suitable for sharpening good knives, but I very nearly sent these stones back, and I never send anything back.

Guys with little experience breaking in diamond stones might take notice. The stones were the same size, and purchased at the same time, but they were different grits. Was I unlucky? Three different stones? I know all diamond stones need to be broken in, or at least tested on scrap, but these stones were in pretty crude condition out of the box.

I knew how to correct the problem but it took a long time. Even if you feel comfortable breaking them in yourself, these stones were too rough for retail sale, in my opinion, and far from the consistent quality I've gotten from Atoma and Ultra Sharp stones, for similiar prices.

One man's experience. I don't sell stones. Take it for what you think it is worth!
 
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Khromo said:
I've got full sets of Atoma, Ultra Sharp, and DMT bench stones, and until recently I would have recommended buying whichever is on sale. They have all performed very well for me in the past.

I recently purchased the 10x4" DMT stones in coarse, fine, and extra fine. These stones required a very long, very deep break-in process, much different from DMT's I've purchased previously. I finally got them suitable for sharpening good knives, but I very nearly sent these stones back, and I never send anything back.

Guys with little experience breaking in diamond stones might take notice. The stones were the same size, and purchased at the same time, but they were different grits. Was I unlucky? Three different stones? I know all diamond stones need to be broken in, or at least tested on scrap, but these stones were in pretty crude condition out of the box.

I knew how to correct the problem but it took a long time. Even if you feel comfortable breaking them in yourself, these stones were too rough for retail sale, in my opinion, and far from the consistent quality I've gotten from Atoma and Ultra Sharp stones, for similiar prices.

One man's experience. I don't sell stones. Take it for what you think it is worth!
Click to expand...
If I may ask,how long ago did you buy your DMT stones?
 
Robert Ptacek said:
If I may ask,how long ago did you buy your DMT stones?
Click to expand...

I bought a set of 8x3" DMT stones about five years ago. They worked fine, right in the same neighborhood as Atoma and Ultra Sharp. They needed a typical break-in, but all diamond stones, in my experience, need to be broken in. That's not a problem.

The 10x4" clunkers were purchased within the last two or three months. They required some fairly intense work to get ready for a decent blade, they would chip a blade to death as they came out of the box. Sharpening a few beaters would not have gotten these stones up to speed, they needed a lot more care than they should have.

The new 10x4 stones are huge, they only cost about $300 US for medium, fine, and extra fine stones, and after a nasty break-in they work fine. A lot of guys would have sent them back, and they would have been right to do so. A lot of guys would not have been able to get them cleaned up, so my opinion is the stones I got are fine for the advanced DIYer, not suitable for the casual user. If I ever needed to buy new diamond stones, I would stick with Atoma or UltraSharp based on my experience.
 
The reason I ask is about 7 months ago I bought a coarse/fine 8 inch interrupted surface stone and the coarse side was fine but the fine felt like a cheese grater.I took an old kitchen knife to it and it smoothed right out.I knew they needed to be broken in and it didn't take much effort.My theory is an excess of grit around the perforations.I am interested in your theory about yours.
 
I've used DMTs for decades, from Diafolds to 6" bench hones to 8X3" bench hones. The DMT DuoBase stand is worth getting, I use BreakFree CLP to clean mine; it lifts the swarf right off.
 
Robert Ptacek said:
...My theory is an excess of grit around the perforations.I am interested in your theory about yours.
Click to expand...

I don't have enough information to form a theory of why the stones were poor products, Robert. Just three stones that should not have made it past QC. Way too many stubborn high spots, all over all three stones, they were unusable for anything but shitty garden tools as they came out of the box.

If I ever have to buy diamond bench stones in the future, I will not buy DMT's, I will buy Atomas or Ultrasharps, as they have never sold me third-rate stones.
 
Khromo said:
I don't have enough information to form a theory of why the stones were poor products, Robert. Just three stones that should not have made it past QC. Way too many stubborn high spots, all over all three stones, they were unusable for anything but shitty garden tools as they came out of the box.

If I ever have to buy diamond bench stones in the future, I will not buy DMT's, I will buy Atomas or Ultrasharps, as they have never sold me third-rate stones.
Click to expand...
Thanks for your reply
 
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