This is a full lapping plate, which is a diamond 'pad' fixed to an aluminum substrate.
The Atoma 140x is a very aggressive/coarse and effective lapping plate, it’s perfect for removing a lot of stock material quickly. I use the 140x plate to do the basic leveling work on a new unlapped stone. I follow up with the 400x Atoma to finish up the job.
Natural and synthetic sharpening stones need to be lapped dead flat to work properly. Proper maintenance of any sharpening stone means those flat surfaces have to be checked for flatness regularly. Every time you hone a razor or sharpen a tool or knife on any stone, the working surface wears. While you don’t have to lap every stone every time you hone, there are some stones that do need that treatment, and – at some point – every sharpening stone will need to be lapped back into working condition.
These Atomas cut fast, they’re aggressive but they leave a comparatively even surface on the stone. They’re easy to use, clean and they are, basically – maintenance free; in other words, they don’t have to be lapped. The substrate is a solid block of aluminum that’s been milled flat and the diamond surface is extremely durable and very long lasting.
After two years of side-by-side use, I can say confidently that the Atoma diamond plates outperform DMT plates by a significant margin in every single way.