In his SEM study
The Honing Progression Todd Simpson gives edge apex in microns for edges set edge-leading on bench stones of progressively finer grits. The edge set on Shapton JIS #4000 has apex width of 0.3 micron
Edge-on view image after Shapton 4k, showing an apex width in the range of 0.3 microns.
When I was checking accuracy of our computer software to set grinding angle, I took BESS scores of knives ground edge-leading on the Tormek Japanese wheel #4000 - on this wheel knives get sharpness averaging 152 BESS. As we know, the sharpness score of 50 BESS indicates 0.1 micron apex, and the sharpness tester reading of 152 BESS tells us of 0.3 micron apex width, which is consistent with the scanning electron microscopy in the Todd's study.
Details follow.
Global kitchen knives ground at 14 dps, edge set on Tormek-8 on a CBN wheel #1000 diameter 254.2 mm - a tiny but visible burr scoring near 300 BESS.
Edge-leading deburring on a Tormek-7 machine on an SJ wheel #4000 diameter 240.7 mm scores:
Tormek SJ wheel #4000, grinding at the exact edge angle = 150 BESS (knife 1) and 154 BESS (knife 2).
Tormek SJ wheel #4000 at -0.1 degree less than the edge angle, i.e. at 13.9 dps = 168 BESS (knife 3).
Tormek SJ wheel #4000 at -0.2 degree less than the edge angle, i.e. at 13.8 dps (knife 4):
1 pass each side = 209 BESS,
2 passes each side = 149 BESS,
3 passes each side = 135 BESS.
I could see how with each pass the band of polished metal was spreading from the edge shoulder towards the apex till reached it on the 3rd pass.
Tormek SJ wheel #4000 at -0.3 degree less than the edge angle (knife 5) = 250-330 BESS; after 2 alternating passes a band of polished metal was clearly visible on the edge bevel near the shoulder not reaching the apex.
(In our estimate, real life accuracy of our computer software, given the manual setup, is 0.1 degree.)