Conversion Tables
| US and ASTM Std. Sieve Number | Actual Opening Size (In) | Micron Rating |
| 10 | 0.0787 | 2000 |
| 12 | 0.0661 | 1680 |
| 14 | 0.0555 | 1410 |
| 16 | 0.0469 | 1190 |
| 18 | 0.0394 | 1000 |
| 20 | 0.0331 | 840 |
| 25 | 0.0280 | 710 |
| 30 | 0.0232 | 590 |
| 35 | 0.0197 | 500 |
| 40 | 0.0165 | 420 |
| 45 | 0.0138 | 350 |
| 50 | 0.0117 | 297 |
| 60 | 0.0098 | 250 |
| 70 | 0.0083 | 210 |
| 80 | 0.007 | 177 |
| 100 | 0.0059 | 149 |
| 120 | 0.0049 | 125 |
| 140 | 0.0041 | 105 |
| 170 | 0.0035 | 88 |
| 200 | 0.0029 | 74 |
| 230 | 0.0024 | 62 |
| 270 | 0.0021 | 53 |
| 325 | 0.0017 | 44 |
| 400 | 0.00142 | 36 |
| 550 | 0.00099 | 25 |
| 625 | 0.00079 | 20 |
| 1250 | 0.000394 | 10 |
| 1750 | 0.000315 | 8 |
| 2500 | 0.000197 | 5 |
| 5000 | 0.000099 | 2.5 |
| 12000 | 0.0000394 | 1 |
