Atoma Diamond Sharpener Plate

by Tsuboman


Atoma Diamond Sharpening Plates are products of Tsuboman, a superb Japanese manufacturer with very refined products. These plates are made of mono-crystalline diamonds as the abrasive surface on stainless steel (body made of 10mm think machined aluminium plate). The quality and durability of these Atoma plates are of the highest we could find, with precision made surfaces that have high uniformity. These plates remain flat after continued use, and the diamond surface plate can be replaced after a few years without buying another baseplate. 

Made in Japan


  • Origin: Kure, Hiroshima Prefecture, Japan 
  • Dimension: 210 x 75 x 12mm
  • Weight: 745g

Atoma #140

The Atoma 140 is the go-to diamond plate for me when it comes to repairing chipped knives, or flattening whetstones. The biggest benefit to using diamond plates over whetstones in this grit range is longevity, and flatness - you don’t have to worry about either. I have been using the same Atoma 140 for all of my repairs since 2017. I also use the Atoma 140 to flatten any whetstones that need flattening, from the coarsest to the finest. It is my pick for best all-around flattening plate / fixing diamond plate. - Ryky

Atoma #400

The Atoma 400 has been used in my sharpening kit to replace whetstones from 320-500 grit range. This grit range can be considered the upper end of “fixing” stones, or the lower end of “sharpening” stones. The Atoma 400 is coarse enough to flatten whetstones, but also fine enough to replace traditional whetstones up to 500 grit. - Ryky

Atoma #600

The Atoma 600 is a great option for those who want a replacement for whetstones from the 500-800 grit range, but will last much longer than traditional whetstones. Whetstones in this grit range are considered coarse sharpening stones, and will bring dull knives back to life, but are generally a bit softer and faster wearing than most 1000 grit stones, so the Atoma 600 is a perfect diamond plate to get, that will give you the benefits of a coarse sharpening whetstone, but will last much longer, and will never need flattening. - Ryky

Atoma #1200

The Atoma 1200 is a great substitution for those who want the longest lasting 1000 grit equivalent sharpening plate.  The edge you get on the Atoma 1200 is comparable to a traditional 1000 grit whetstone, but the diamond plate never needs flattening or correcting.  If I showed you a knife sharpening with the Atoma 1200, and a knife sharpening on a 1000 grit whetstone, you will not be able to tell the difference between them, and their sharpness would be the same. While it can be used for light lapping work on whetstones, to better maintain an even or flat surface, it is not the optimal use for this diamond plate.  - Ryky

Which Grit?

Atoma 140 vs Atoma 400: Get the 140 if you plan on doing lots of repairing of chipped or damaged knives, or want a diamond to be used at a flattening plate that can also handle knife repairs. If you want a fast cutting diamond stone to use on dull knives, but want a finer edge than what the Atoma 140 leaves you with, get the 400.

Atoma 400 vs Atoma 600: The Atoma 400 is faster, and better suited for very dull knife edges, while the Atoma 600 will give a finer finished edge. Get the Atoma 600 if you already own the Atoma 140, or a whetstone in a similar grit range. There is no need to have two stones too close in grit. 

Grit Model Use
Atoma #140 ATM75-1.4E Repairing chipped or damaged knives. 
Atoma #400 ATM75-4E On dull knives. Gives you finer edge than #140
Atoma #600 ATM75-6E Even finer finished edge. Great combo with #140
Atoma #1200 ATM75-12E Substitution for a #1000 grit whetstone


Ryky’s Repairing Combination: #140 / #600: After repairing any knife on the Atoma 140, I take that knife right to the 600, before going on a 1000 grit whetstone.

Ryky’s Maintenance Combination: #600 / #1200: When I am short on time, and cannot pre-soak a whetstone, hopping on the Atoma 600 is quick and easy, followed by the Atoma 1200. I can strop right after the Atoma 1200, and get a usable edge in any kitchen.

Double-sided Atoma Plate

To make a double-side Atoma plate seen in Ryky's videos, pick up a grit from this listing, then pick up a spare blade (replacement plate) of another grit you are likely to use. They come with adhesives pre-attached, so you don’t need additional tools for attaching the spare blades.


After use, please make sure to remove as much debris from the plate, and wipe dry with cloth.  Discoloration on diamond plate surface is normal, due to heat build up during use. This will not damage the integrity of the plate.

Customer Reviews

Based on 4 reviews
ad cr (Manchester, GB)
Quality product

I prefer diamond plates to water stones for the more aggressive sharpening and this is about the best diamond plate I can find.

Brian Flynt
Solid diamond plate!

Works great for leveling your whetstones and for heavy blade repair.

jed reyes (Anchorage, US)

Great item i love it

Gabriel Querol (Chicago, US)
Atoma 609

Simply peerless. Perfectly flat and consistent, just as all my other Atoma plates.

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