Grit Table / waterstones / Suehiro Gokumyo
Product, maker micron
Ultra-fine finishing stones
Suehiro states a micron for the Gokumyo ultra-fine stones, one of the few waterstone lines here that publishes a particle size at all. #20000 at 0.5 micron, #13000 at 1.0. Maker-published (hollow), no distribution given.
Each grade below shows its size in microns, its spread (the published distribution, where a maker or standard gives one; most makers publish none), and where that size lands on the reference scale, a shared yardstick for reading grit numbers across makers.
Suehiro's own figure for the predecessor stone, cited on the GMN200 page.
Suehiro's own published particle size.