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Grit Table / standards / ISO 8486-2 / FEPA-F

Standard

ISO 8486-2 / FEPA-F

Bonded-abrasive (grinding wheel) microgrit grading

ISO 8486-2 (the FEPA-F microgrits) grades the abrasive grain in grinding wheels. Each grade carries a full ds3 / ds50 / ds94 distribution, recovered here from free national adoptions (BIS IS 15288) and manufacturer tables, cross-checked across three sources. F1200 and finer switch the fine tail to ds80.

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
503020105321
coarserfiner
inkmeasured or standardmaker figureour estimate
shapeknown distributionpoint, spread unknown
F230Standard-defined
median
53 µm

spread 82 to 34 µm · reference scale about #250

F240Standard-defined
median
44.5 µm

spread 70 to 28 µm · reference scale about #290

F280Standard-defined
median
36.5 µm

spread 59 to 22 µm · reference scale about #340

F320Standard-defined
median
29.2 µm

spread 49 to 16.5 µm · reference scale about #410

F360Standard-defined
median
22.8 µm

spread 40 to 12 µm · reference scale about #530

F400Standard-defined
median
17.3 µm

spread 32 to 8 µm · reference scale about #670

F500Standard-defined
median
12.8 µm

spread 25 to 5 µm · reference scale about #890

F600Standard-defined
median
9.3 µm

spread 19 to 3 µm · reference scale about #1250

F800Standard-defined
median
6.5 µm

spread 14 to 2 µm · reference scale about #2050

F1000Standard-defined
median
4.5 µm

spread 10 to 1 µm · reference scale about #2750

F1200Standard-defined
median
3 µm

spread published · reference scale about #4000

F1500Standard-defined
median
2 µm

spread published · reference scale about #6000

F2000Standard-defined
median
1.2 µm

spread published · reference scale about #8000