U.S. Mesh vs. Micron

Filter media is sometimes rated in U.S. Mesh instead of microns. This gauge standard is the number of openings per linear inch using standard wire diameters. Wire mesh measures the number of wires (or threads) per linear inch, not the size of the holes between them. As the number of wires per inch goes up, the size of the holes (in microns) goes down.

 

The chart below roughly converts between U.S. Mesh, microns, and fractions of an inch. There is no simple formula to convert between microns and wire mesh because it would have to account for changing wire diameter.

U.S. Mesh
Microns
Inches
10
2000
0.0787
12
1680
0.0661
14
1410
0.0555
16
1190
0.0469
18
1000
0.0394
20
840
0.0311
25
710
0.0280
30
590
0.0232
35
500
0.0197
40
420
0.0165
45
350
0.0137
50
297
0.0117
60
250
0.0098
70
210
0.0083
80
177
0.0070
100
149
0.0059
120
125
0.0049
140
105
0.0041
170
88
0.0035
200
74
0.0029
230
62
0.0024
270
53
0.0021
325
44
0.0017
400
37
0.0015
550
25
0.0009
800
15
0.0006
1250
10
0.0004