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Surface finish conversion from Microns to inches

My customer is calling out a specification of 3 microns surface finish on a part. What is it in inches ? How do I convert that back to inches?

AL Podolak
Machining - Macon, Georgia, USA
2004

Here it is: 25.4 microns = 1 mil (0.001"). So multiply by 1000, i.e., 25400 microns = 1 inch.

Mandar Sunthankar
- Fort Collins, Colorado
2004

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First of three simultaneous responses --

There are 25.4mm in one inch and 1,000 microns in 1mm, so there are 25,400 microns in one inch.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004

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Second of three simultaneous responses --

The Micron to Mil breakdown is as follows 1 Micron is = to .03937 Mils, or in reverse 1 Mil is = to 25.4 Microns

Jeffrey D Sawczsyzyn
Transit Manufacturer - Hornell, New York
2004

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Third of three simultaneous responses -- 2004

"micron" is slang for micrometer. 1 meter = 39.37 inches therefore, 1 micrometer = 39.37 microinches, or, 1 micron = 39.37x10E-6 inches

Hope this helps.

Jim Petri
connector development - Wenatchee, Washington