Shop Filters.

  Mesh Micron Inches  
  4 5205 0.2030 GRAVEL
8 2487 0.0970
10 1923 0.0750
14 1307 0.0510
18 1000 0.0394
20 840 0.0331
  25 710 0.0280 SEWING NEEDLE
30 590 0.0232
35 500 0.0197
40 420 0.0165
  45 350 0.0138 BEACH SAND
50 297 0.0117
60 250 0.0098
70 210 0.0083
  80 177 0.0070 RAZOR BLADE
100 149 0.0059
120 125 0.0049
140 105 0.0041
170 88 0.0035
Coarse Filtration 200 74 0.0029 HUMAN HAIR
230 62 0.0024
270 53 0.0021
325 44 0.0035
Fine Filtration 400 37 0.0015 SMALLEST VISIBLE PARTICLE
550 25 0.0009
800 15 0.0006 BUTTERFAT GLOBULES
1250 10  
Micro Filtration --- 5 0.0002 RED BLOOD CELLS
--- 1 0.000039 YEAST AND FUNGI

See Filtration Ratings Chart