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 sizemicrons, log

5030201053210.50.3

coarserfiner

inkmeasured or standardmaker figureour estimate

shapeknown distributionpoint, spread unknown

60 micronMaker-published

60 µm

468L microfinishing film (silicon carbide), PSA.

spread not published · reference scale about #230

40 micronMaker-published

40 µm

263X / 266X aluminum oxide (266X is the PSA variant); 468L silicon carbide also at 40 micron.

spread not published · reference scale about #320

30 micronMaker-published

30 µm

261X aluminum oxide; 461X / 468L silicon carbide.

spread not published · reference scale about #400

15 micronMaker-published

15 µm

461X / 468L silicon carbide (468L PSA).

spread not published · reference scale about #760

9 micronMaker-published

9 µm

261X aluminum oxide; 461X / 468X silicon carbide (468X PSA).

spread not published · reference scale about #1300

5 micronMaker-published

5 µm

261X aluminum oxide; 461X / 466X silicon carbide (466X PSA).

spread not published · reference scale about #2500

3 micronMaker-published

3 µm

261X aluminum oxide; 661X diamond also at 3 micron.

spread not published · reference scale about #4000

1 micronMaker-published

1 µm

262X aluminum oxide; 661X diamond also at 1 micron.

spread not published · reference scale about #8850

0.5 micronMaker-published

0.5 µm

Current 3M product at this grade is diamond (661X / 661XU).

spread not published · reference scale about #13050

0.3 micronMaker-published

0.3 µm

261X aluminum oxide.

spread not published · reference scale about #17550