Grit Table / film / 3M lapping film
Product graded in microns
3M lapping film
Microfinishing film, micron-graded
3M grades its film directly in microns, printed on the roll . Like other micron media this is a maker figure, no grit-number pretense but also no independent measurement, and no distribution is published, so each grade is a single point.
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
30 10 3 1 0.3
coarser finer
ink
shape
60 micron Maker-published
468L microfinishing film (silicon carbide), PSA.
spread not published · reference scale about #230
40 micron Maker-published
263X / 266X aluminum oxide (266X is the PSA variant); 468L silicon carbide also at 40 micron.
spread not published · reference scale about #320
30 micron Maker-published
261X aluminum oxide; 461X / 468L silicon carbide.
spread not published · reference scale about #400
15 micron Maker-published
461X / 468L silicon carbide (468L PSA).
spread not published · reference scale about #760
9 micron Maker-published
261X aluminum oxide; 461X / 468X silicon carbide (468X PSA).
spread not published · reference scale about #1300
5 micron Maker-published
261X aluminum oxide; 461X / 466X silicon carbide (466X PSA).
spread not published · reference scale about #2500
3 micron Maker-published
261X aluminum oxide; 661X diamond also at 3 micron.
spread not published · reference scale about #4000
1 micron Maker-published
262X aluminum oxide; 661X diamond also at 1 micron.
spread not published · reference scale about #8850
0.5 micron Maker-published
Current 3M product at this grade is diamond (661X / 661XU).
spread not published · reference scale about #13050
0.3 micron Maker-published
261X aluminum oxide.
spread not published · reference scale about #17550
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.