Diamond Plates VS Naguras

Written by Maksim

This is one of the most common questions I get — should I use a diamond plate or a nagura on my natural stone ? The short answer is: diamond plate for flattening, nagura for making slurry. They are not interchangeable. Each one does its job well — but if you use them for the wrong job you will get poor results and potentially damage your stone.

Diamond Plates — What They Are Good For

Diamond plates are excellent for one thing: flattening your stone. They cut fast, they are hard and flat, and they get a dished stone flat again very effectively. For this purpose I recommend the Atoma diamond plates — they are consistent and not too aggressive. The 140 grit for heavy flattening, the 400 for light maintenance flattening.

After flattening with a diamond plate always do a finishing pass with a tomo nagura or another natural stone to smooth out the scratches left by the diamond plate. Read more about this in the How To Use Guide.

Why Diamond Plates Are Wrong for Making Slurry

Some people use a diamond plate to scratch the surface of their natural stone to raise slurry. I understand why — it is fast and convenient. But this is a mistake that will cost you the performance of your stone !!!

Here is what happens when you use a diamond plate to make slurry:

• You remove big chunks from the stone surface. A diamond plate digs into the stone aggressively. The particles released are irregular chunks — three dimensional lumps of stone material, not the flat plate-shaped particles you want.
• Chunks cut differently than plates. On a natural stone, the cutting particles are released naturally as flat plates — like scales or flakes. These plates align with the blade and polish in a controlled way. Chunks are random shapes that cut in random directions. The result is that your stone performs more like a synthetic than a natural stone.
• You can cause uneven texture in the slurry. A chunky slurry gives inconsistent results — sometimes it cuts well, sometimes it scratches, sometimes it feels completely wrong. You lose the fine control that a natural stone is supposed to give you.
• You are wasting your stone. You are removing material from an irreplaceable natural stone unnecessarily and aggressively. Good natural stones cannot be replaced — treat them with care !!!
• Good diamond plates are expensive too. Cheap ones gouge the stone surface badly. A cheap diamond plate doing slurry work is even worse than an expensive one — but even the best diamond plate gives you worse slurry than a nagura.

Plates vs Chunks — The Science

This is explained in more detail in the JNS Grit, Fines and Hardness 

Naguras — What They Are Good For

A nagura rubbed on the surface of your natural stone releases slurry gently and correctly — particles come off as plates, not chunks. This preserves the character of your stone and gives you full control over the slurry progression.

The other big advantage of nagura slurry that nobody talks about: the more you use a nagura on your stone, the better the stone performs over time. The nagura slowly conditions the stone surface — it gets finer and more refined with each session. A stone that has been regularly used with Asano nagura for years performs better than a new stone fresh out of the box.

For which nagura to use and when, read the Naguras wiki page and the Stones Recommendations page.

That is it :) Simple rule — diamond plate is a flattening tool, nagura is a slurry tool. Use each for its purpose and your stones will last longer, perform better, and give you much more control.

If you have questions about your specific setup just message me on WhatsApp.