Diamond Flattening Stones vs Silicon Carbide Stones

[Karen O]

I am new to the world of Japanese knives and upon my decision to purchase a few basic knives, I decided that I would do my own sharpening. My sharpening stone set consists of the 400, 800, and 3000 Naniwa Professional (Chosera) stones. My question concerns a flattening stone. What are your thoughts on a diamond flattening stone versus a silicon carbide (carborundum) flattening stone? The DMT extra coarse stone at 120 and the Atoma Plate at 140 appear to be popular. Could grits this coarse damage the 3000 grit Naniwa?

[jacko9]

I have the Atoma 140 plate and it will not damage your 3000 grit stone. It will leave a rougher finish on the stone that will smith out with use but, in limited experience (40 years) it will be just fine. If your concerned about the course marks left with the Atoma 140 you might want to consider the Atoma 400. I have two Atoma plates and one DMT which has worn out rather too fast in my opinion. I bought a carborundum sharpening stone but never used it since the Atoma works so well. I have stones ranging from 150 to 8000 grit in many manufactures as well as natural stones and they all flatten very well with the Atoma (and I think the 400 will suit you well).

Jack O

[Gregory27]

Honestly, if you're just looking for flattening, consider the CKTG 140 plate:

https://www.chefknivestogo.com/140grdistflp.html

Great value. Also works great for repair work on knives, something that those silicone carbide flatteners can't do. And no, a coarse diamond plate won't wreck your stones. Like Jacko said, they'll just leave a slightly more aggressive surface which will even out with a bit of use of the stone.

[salemj]

^^^This. Also, Mark sells a cheap 400/1000 diamond plate that could also be used for flattening. It would probably work well on all your stones and may work better using the 1k side on the 3k stone. Just another thing to consider.

[Jeff B]

The CKTG 140 plate will work just fine. Just use lighter pressure on the 3k and you'll have no problems.

[Kit Craft]

I agree, I use the 140 CKTG for about everything and smooth over with a small 400 if needed. However, I do fully intend to get one of those big Dia flat plates that are 10x4. Would be cool if Mark could get something similar for us on the cheap!

As for the 400/1k, this is regurgitation of what I have heard but both SteveG and Jason B. have said that it only works "okay" for flattening but remarkably well for removing metal. Or at least for a cheap plate. Paraphrasing, of course. Was like, years ago, I can't remember the exact phrasing. No first hand experience though!

[gladius]

Mark used to sell DiaFlat - very good plate, highly recommended!

The CKTG 400/1000 works fine for flattening mid/fine stones. Of course if you have deep dishing then you'd want to start on a coarser plate but for routine flattening it is fine.

[Kit Craft]

Thanks on both accounts. Sure need a bigger plate. Small plates and big stones work but...not near as convenient.

[Jeff B]

Mark sold the Diaflat before they gained the rep they have now. He had a hard time selling them so gave them up.

[Radar53]

I have both the Atoma 140 & 400 & I use the 140 on stones up to 1k & the 400 on stones 1k & above. The exception to this is if a higher grit stone needs quite a lot of flattening. If my grid pattern mark-up indicates this, I use the 140 until the remaining grid pattern is pretty minimal & then finish it with the 400.

Am I just being too OCD as usual about this??

[ken123]

So to answer a few specific questions. The 140 Atoma and presumably other somewhat similar plates will work fine on a 3k stone - recommended. It is your most versatile plate. For stones coarser than about 220 grit ( eg Shapton glass 220), I use a coarser waterstone like the 24 grit Nubatama - a very hard stone for its grit. This cuts through stone fast, but it will eventually dish a bit unlike diamond plates. I flatten the flattener with another 24 grit Nubatama. I use my diamond plates a lot. Just flattened 100 stones a couple days ago in one day with an Atoma 140. The Atomas just keep on going and going. I long since gave up on DMTs

I have 46 and 60 grit diamond plates. In addition to grinding crazy fast, they are perfect for flattening coarser stones especially if you dished them a lot. King stones come to mind ...

What many people don't realize is that a 60 grit or even a 220 grit stone after flattening with a 140 diamond plate is wimpy. The particles on the stone surface have been cleaved by the diamond plate into fractional sized particles that are just not aggressive. You need to rough up the surface again to give your stones a 'new set' of [stone] balls to work with

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Ken

[Radar53]

Ken, thanks for coming back and also for the insights.

[jdwhitak]

I have a Shapton Glass Diamond lapping plate and a DMT X-Coarse. I find the coarse diamond stones too aggressive. The DMT X-Coarse left some serious scratch marks on my Hard Black Arkansas. Right now I'm experimenting with using 180 grit SiC sandpaper on a glass plate for lapping. So far so good. A lot smoother finish than the DMT.

[ken123]

The hard Arkansas stones wear slowly so a coarse lappping plate will leave deeper scratches that you can optionally refine further even with 1200 or 3k diamond plate. Largely unnecessary as a few honing sessions will also polish the surface adequately.

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Ken