Grit Table / standards / CAMI / ANSI
Standard
CAMI / ANSI
North American coated-abrasive grading, ANSI B74.18
CAMI (ANSI B74.18) is the North American sandpaper grading, and it does not match FEPA past about 240. CAMI 400 is about 23 micron; FEPA P400 is about 35. CAMI specifies an average size, not a percentile range , so every grade here is a single median point, by the nature of the standard rather than a paywall.
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 size microns, log
300 100 30 10
coarser finer
ink
shape
CAMI 36 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #30
CAMI 40 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #40
CAMI 50 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #50
CAMI 60 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #60
CAMI 80 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #80
CAMI 100 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #110
CAMI 120 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #130
CAMI 150 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #150
CAMI 180 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #180
CAMI 220 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #210
CAMI 240 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #250
CAMI 280 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #300
CAMI 320 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #350
CAMI 360 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #420
CAMI 400 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #510
CAMI 500 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #610
CAMI 600 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #720
CAMI 800 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #940
CAMI 1000 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #1250
CAMI 1200 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #2050
CAMI 1500 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #2350
CAMI 2000 Standard-defined
Coarse grade, sieve-graded.
spread sieve-graded · reference scale about #2500
On these numbers. Defined by the standard, tier standard-defined.
This is reference, not a recommendation. Particle size is defined by the abrasive grading standards (ISO 8486, ISO 6344, JIS R6001, ANSI B74, FEPA); the full references are listed and linked here . The data is free to use under CC BY 4.0 ; please credit Zen-Wu Toolworks.