Originally Posted by
Steel
So many different angles to go here. If we are talking actual grit size I don’t think they are that small. I think an Arkansas is around a 1200 grit equivalent but due to the binder (or lack there of) it can act like a much higher grit stone as it burnishes. How the stone cuts and how the cutting particles are arranged can also have a dramatic effect. Then you get into another ball park entirely when you talk about “friable” grit (if that’s ever been proven I don’t know). Or you can talk about the perceived edge you finish with and the shave result.
For me, the perceived Edge’s of some of my thuringian and jnat edges have been over 12k and there is another difficulty- I don’t know that I can tell the difference between a 15k edge and a 16k or 20k edge for that matter. If I’m honest. I think I can but.....yeah.
The shape of the edge, I believe, has a profound effect in the end too. A rounder (think splitting maul or apple seed) edge is much more comfortable but not necessarily more sharp. There’s another can o worms too.
Of course this is only my current, imagined, subjective, opinion. I have very little objective scientific basis for any of it. So take it for what it’s worth.
PS. I vote for 20k although it’s only a subjective guess.