What do I have ?

[Pete Allan]

While sanding on a blade the other day the barrel maker that rents a spot in my shop handed me some"plastic sand paper". It is made by 3M and is graded 30u, 40u and 60u. The "u" is actually an upside down small h but I don't have one of those on this key board. Does any one know about this stuff like what is the grit size in numbers that I am familar with like 400 or 600 ??? I tried out a small piece and found it to cut very well and as long as I kept it wet with WD40 it did not seem to get dull.
Thanks much

 

[Sando]

That's micro finish paper. I use the belts for various tasks. I like 40/30/15/9 Those sizes are microns.

Great stuff. I like it it's washable.

Here's a grit equivalent chart for you.

http://www.ameritech.net/users/knives/grits.htm

Steve