Guide to Abrasive Sizes
There is a potentially baffling number of different ways of measuring the sizes of abrasives. It can sometimes seem that no two suppliers use the same terminology. The most sensible way would be to give the micron size so that direct comparisons can be made.
Elutriative time is the time a particle will take to settle in a 1 metre column of water. Elutriation is a simple way of ensuring that abrasives do not contain larger-sized particles.
| Mesh | Decimicron | 'M' | Size in microns | Elutriative time |
| 60 | - | M60 | 293 | - |
| 80 | - | - | 185 | - |
| 100 | - | M100 | 148 | - |
| 120 | - | - | 123 | - |
| 180 | - | M180 | 86 | 1 min |
| 220 | - | - | 73 | - |
| 280 | - | - | 39 | - |
| 320 | - | - | 37 | - |
| 400 | - | - | 34 | - |
| 600 | - | - | 25 | - |
| - | 225 | - | 22.5 | - |
| 700 | - | M302 | 22 | 5 min |
| - | 175 | - | 17.5 | - |
| 850 | - | M302½ | 17 | 10 min |
| 1000 | - | M303 | 15.5 | 20 min |
| - | 125 | - | 12.5 | - |
| 1300 | - | M303½ | 11 | 40 min |
| - | 95 | - | 9.5 | - |
| 1800 | - | M304 | 8 | 60 min |
| 3000 | - | M305 | 5 | - |
