Quote Originally Posted by onimaru55 View Post
Here's some empirical, non scientific, maybe even pleonastic statements.

I shave off an Atoma 1200 diamond plate slurry on my Nakayama Asagi.
I can also shave off the same stone & a fine Tomo slurry but I won't shave off any Nagura stage.
So I say all Nagura, except a Tomo are coarser than a diamond plate slurry & how you get to end game does'nt much matter.
Ive shaved off of all of them and there is a a definite refining of the edge in the progression. Continuous sharp and smooth differences between them. According to your comment, then I should forgo the 4k in a progression as its not as fine as my 20k. I think we would all agree that the 4k is necessary or a link is broken. And a nagura finished edge at that level is much smoother in the shave test than a synthetic 4k IME. I have a hideriyama suita that is maybe 5k but leaves no scratches at 10x,(there are scratches as the haze is just that, just very shallow ones) just a haze. I have never experienced that with a synthetic stone at that level so something else is going on.