Thread: Atoma 400 lapping question

Originally Posted by kelbro

I would use a screwdriver shank or chisel shank. A few back and forth laps with slight pressure should knock down any high points.

This is necessary for DMT plates, but I don't think that it is for Atomas. The ones I've used didn't seem to have high points.

I just last week got a replacement Atoma 600 plate. I stuck it on the back side of my near worn out 400, (which I'll keep for making slurries) it's first three or four usages were to lap a jnat and it was very sharp at first and evened out over four or five minutes. I looked at its surface under a loupe and I could see how it becomes worn. I also have an Atoma 1200 that is near new, so I get a good idea of the levels of wear, between the 4 year old 400 and the new 600/1200. I wouldn't say they need breaking in but I feel like for that first dozen or so laps on it, it is extra sharp, call it what you like, but your second use of it is different to the first.

Mine was a little 'proud' as well. Just took a few laps with the chisel (light-moderate pressure) to take away the scratchiness.

Originally Posted by bobski

I just last week got a replacement Atoma 600 plate. I stuck it on the back side of my near worn out 400, (which I'll keep for making slurries) it's first three or four usages were to lap a jnat and it was very sharp at first and evened out over four or five minutes. I looked at its surface under a loupe and I could see how it becomes worn. I also have an Atoma 1200 that is near new, so I get a good idea of the levels of wear, between the 4 year old 400 and the new 600/1200. I wouldn't say they need breaking in but I feel like for that first dozen or so laps on it, it is extra sharp, call it what you like, but your second use of it is different to the first.

Originally Posted by kelbro

Mine was a little 'proud' as well. Just took a few laps with the chisel (light-moderate pressure) to take away the scratchiness.

Yes, it certainly won't hurt to do a bit of breaking in, but I remain amazed at just how consistent the height is on the Atomas.

True, Ron, for the price, the Atoma are a great buy, and of course you get guaranteed 'flat' hones. I just finished lapping a big Ozuku, that took near a half hour on the brand new #600, I had a look at the surface of the #600 pre and post lapping and it stood up to that work with very little wear. It doesn't get mentioned often re the Atoma, but you can make them double sided by purchasing a replacement sheet and sticking it to the reverse side, it saves a few dollars and works fine. I have the new #600 replacement sheet, which I stuck to the back of the old #400 plate. Stuart from Tools from Japan has a video on his site of how to stick on new sheets. It's pretty easy, and they will not move once stuck down. They use special double sided tape which is amazingly strong.

I think the consistency of the Atoma plates has a lot to do with the diamond grit grading. The DMT plates seem to have a higher occurrence of random larger diamond particles distributed throughout the hone. The Atomas don't have nearly as many, so they don't have as much of an issue with high particles causing seemingly random deep scratches. Not sure if DMT does this on purpose for some perceived benefit or if they're just sloppy with their grading process.

Honestly, I never have used my Atomas for lapping. I only use them for steel, and because they are so uniform in diamond height, they work well for honing. I use the 400 for major blade repair work and follow it with the 1200. I only use the 140 for machetes.