Hi all ...

sanding grit sizes ...

9 micron = 3200 grit
5 micron = 4000
3 micron = 8000
2 micron = 12000

so what is ....
1 micron = ?
0.3 micron = ?

Tks

A micron is 1000 of a millimeter. Or 0.001mm.

I used to work in a bearing manufacturing plant where almost everything was measured in microns. Our lab had the ability to measure 0.0001mm and there was a really interesting illustration that was posted everywhere. It showed the relationship of different sized circles and was very effective at showing how small a micron really is.

Basically it was a circle about 10cm in diameter which represented a period on a piece of paper. There was another circle about 1cm in diameter which represented the thickness of a human hair. The last circle was just a 1mm wide dot which represented a micron. Of course this is from memory (last time I saw this image was 4 years ago) so I might be off on my scale a bit.

To reference your question below, I believe that grit size is measured by the particle count in a square inch. 1 micron (I think) equates to about 24000 grit. Could be wrong on that though.

Cheers,
SG