Convert from micron to mil

Unit Definition (micron)
A unit of length. One Micron = 39 millionths of an inch (.000039"). Contaminant size is usually described in microns. Relatively speaking, a grain of salt is about 60 microns and the eye can see particles to about 40 microns. Many hydraulic filters are required to be efficient in capturing a substantial percentage of contaminant particles as small as 5 microns. A micron is also known as a micrometre, and exhibited as µm.

Unit Definition (mil)
The mil is a unit of distance equal to 0.001 inch: a "milli-inch," in other words. Mils are used, primarily in the U.S., to express small distances and tolerances in engineering work. One mil is exactly 25.4 microns, just as one inch is exactly 25.4 millimeters. This unit is also called the thou. With the increasing use of metric units in the U.S., many machinists now avoid the use of "mil" because that term is also a handy slang for the millimeter.