Quote Originally Posted by eleblu05 View Post
those conversions are way off 4000= 3.68 micron 8000=1.84 micron 16000=.92
I rechecked with a second 3M rep, and he confirmed what the earlier rep said, so the numbers are correct for a 3M product sanding progression. He said that they are using an ANSI grading system which may be where the confusion lies?