Grit Measurement

[Jerry Thompson]

I have often seen "µm" as a measure of the grit in polishing compounds. What does it translate to? It would seem that diamond past @ .1µm would be mighty fine. However I need a translation. Is it finer that an 8k waterstone for example?
Jerry

[Alex Shanku]

microns. 1micron = 10E-6 meters

[Alex Shanku]

Also, I believe 1 micron = 14,000 grit

[Doug Shepard]

Not a complete chart but still handy
http://www.cs.rochester.edu/u/roche/rec.wood.misc/grit.sizes.html

[Eddie Darby]

Here is a link that might help:

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

Japanese 8,000x waterstone is 1.2 microns.
1.2 microns is 0.000047", or close to 1/2 of one ten thousands of an inch.
In other words pretty small.

Human hair is in the area of 40 microns.

[Wilbur Pan]

Yet another link: Article on Popular Woodworking's blog (http://blogs.popularwoodworking.com/editorsblog/True+Grit+Understanding+Sharpening+Grits.aspx) regarding actual grit size and various sharpening systems.

There's a downloadable spreadsheet on that webpage that lines up the different systems, so you'll be able to see that your Hard White Arkansas stone is equivalent to a 1200 grit Japanese waterstone, which is in turn just about equivalent to 800 grit sandpaper in the Scary Sharp system.

[Jerry Thompson]

It seems a though I had a sheet of sandpaper the measured 0.5u. It felt like a slick piece of paper. I am interested it getting a few sheets to send to a friend how is and OCD when it come to sharpening. I sent him a very fine hand made knife that is a using one not one to be brought out and looked at. He is bound to get as polished edge on it he can.
Any help. I want to thank all of you in helping me understand the abrasive qualities of various products.
As far a I can tell my 8000 grit water stone will serve me fine.
Jerry

[Doug Shepard]

LV has the 0.5
http://www.leevalley.com/wood/page.aspx?c=2&p=33004&cat=1,43072