Different standards grade micron powder by different principles — size interval, median diameter or sieving — so no designation has a perfect equivalent in another system. This chart gives the customary approximate mapping used across the trade.

What the chart covers

  • China W grades with nominal micron ranges, W0.25 through W60.
  • GB/T 6406 M-designations (identical in principle to ISO 6106:2013; inspection methods per JB/T 7990-2012).
  • FEPA / ISO 6106 D-grades for micron powders.
  • JIS approximate mesh numbers on a median-diameter basis.
  • Typical use bands: polishing ≈ W0.25–W10, lapping ≈ W5–W20, fine grinding ≈ W20 and coarser.

How to use it

When specifying, give the micron range or W grade rather than a mesh number alone. If you are converting from a current product's datasheet, send us the designation you use and we will confirm the equivalent in writing before quotation.