CBN grinding wheels

CBN superabrasive, graded to FEPA-B

CBN wheels are labelled with mesh numbers, not a published micron. The coarse-to-mid grades (60 to 400) map one-to-one onto the FEPA-B superabrasive standard and inherit its grain-size band; the brands print the mesh number rather than the B-grade, so the link is maker-claimed, not graded-to. The finest grades (600 and up) have no uniform FEPA-B designation, so those stay our micron estimates and do not conform.

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.

Particle sizemicrons, log

10050302010

coarserfiner

inkmeasured or standardmaker figureour estimate

shapeknown distributionpoint, spread unknown

60 grit (B251)Maker-published

231 µm

Range 212 to 250 µm. FEPA-B B251 (mesh 60).

spread 212 to 250 µm · reference scale about #70

80 grit (B181)Maker-published

165 µm

Range 150 to 180 µm. FEPA-B B181 (mesh 80).

spread 150 to 180 µm · reference scale about #90

100 grit (B151)Maker-published

137.5 µm

Range 125 to 150 µm. FEPA-B B151 (mesh 100).

spread 125 to 150 µm · reference scale about #110

120 grit (B126)Maker-published

115.5 µm

Range 106 to 125 µm. FEPA-B B126 (mesh 120).

spread 106 to 125 µm · reference scale about #130

150 grit (B107)Maker-published

98 µm

Range 90 to 106 µm. FEPA-B B107 (mesh 150).

spread 90 to 106 µm · reference scale about #150

180 grit (B91)Maker-published

82.5 µm

Range 75 to 90 µm. FEPA-B B91 (mesh 180).

spread 75 to 90 µm · reference scale about #170

220 grit (B76)Maker-published

69 µm

Range 63 to 75 µm. FEPA-B B76 (mesh 220).

spread 63 to 75 µm · reference scale about #200

320 grit (B54)Maker-published

49 µm

Range 45 to 53 µm. FEPA-B B54 (mesh 320).

spread 45 to 53 µm · reference scale about #270

350 grit (~B54)Maker-published

49 µm

Range 45 to 53 µm. Brand-labelled 350; maps to ~B54, same band as 320, so it conforms to the same fepa-b54 grade.

spread 45 to 53 µm · reference scale about #270

400 grit (B46)Maker-published

41.5 µm

Range 38 to 45 µm. FEPA-B B46 (mesh 400).

spread 38 to 45 µm · reference scale about #310

600 gritOur estimate

30 µm

Range 25 to 35 µm. C-estimated.

spread 25 to 35 µm · reference scale about #400

1000 gritOur estimate

12 µm

Range 9 to 15 µm. C-estimated.

spread 9 to 15 µm · reference scale about #950