Quote Originally Posted by JimmyHAD View Post
I'm still wet behind the ears when it comes to this ... figuratively speaking... so I am letting the big guys fight it out but I am with hi_bud in that ,whatever it is, something is improving (sharpening ?) the edge past 4k.
I think we all agree that something is making the razor sharper past 4k. The disagreement is over precisely what sharpness is, and what causes it, and what is the cause of the improvement in sharpness after the bevel stops improving.

Is it solely the width of the cutting edge?

Is it the width of the cutting edge plus the friction in the 120microns of bevel behind that cutting edge?

Is it the jagginess or lack thereof in the edge?

Is it due to the honing angle?

etc.