Micron-Graded Abrasive Comparison Chart
- FEPA: European abrasives are defined by FEPA (Federation of European Producers of Abrasives) by specifying a limited range of particle sizes for each grade. With this system, a P with the grit size indicates a coated abrasive while an F indicates a bonded abrasive. This is the most commonly used standard world-wide.
- Mesh Grades : The most common methods used in the USA are mesh grades, which are screens of mesh that abrasives can fall through. The finer the mesh, the smaller the grit size, so a 120 mesh is coarser than a 180 mesh.
- Micron sizing : With this system, the grit is measured in microns (one millionth of a metre), and a 120μm (micron) grit is finer than a 180μm grit.
- CAMI: The USA measurements are defined by CAMI ( Coated Abrasives Manufacturers' Institute) and define a grade by the average particle size
- JIS: The Japanese system for measuring abrasives is defined by JIS (Japanese Industrial Standard) document.
The designations given for abrasives are not consistent across the different grading systems. For example the FEPA P800 grade is very similar to the CAMI 400 grade, so it is advisable to confirm which grading system is being used when following project instructions.
The table below shows the abrasive grades most commonly used for metal clay, and has been compiled from information from FEPA, CAMI and 3M™ which is publicly available
| EUROPEAN | U.S. | ||||||
|
FEPA P Grade (coated) |
FEPA F Grade (bonded) |
Particle size range in microns (μm) |
Average particle size in microns (μm) |
CAMI Grade |
Grit | 3M™ Sanding Sponges |
3M™ Wetordry™ Polishing Papers |
| P120 | 125 | ||||||
| 116 | 120 | 3/0 | Medium (Red) | ||||
| P150 | F180 | 100 ± 2.0 | |||||
| 93 | 150 | 4/0 | |||||
| 78 | 180 | 5/0 | |||||
| P180 | F200 | 77 ± 2.0 | |||||
| 66 | 220 | 6/0 | |||||
| P220 | 60 ± 2.0 | ||||||
| P240 | F220 | 58.5 ± 2.0 | |||||
| 53.5 | 240 | 7/0 | |||||
| P280 | 52.2 ± 1.5 | ||||||
| P320 | F240 | 46.2 ± 1.5 | |||||
| 44 | 280 | 8/0 | |||||
| P360 | F280 | 40.5 ± 1.5 | |||||
| 36 | 320 | 9/0 | Fine (Red) | ||||
| P400 | 35.0 ± 1.5 | ||||||
| P500 | F320 | 30.2 ± 1.5 | Green | ||||
| 28.8 | 360 | ||||||
| P600 | 25.8 ± 1.0 | ||||||
| 23.6 | 400 | 10/0 | |||||
| P800 | F360 | 21.8 ± 1.0 | |||||
| 19.7 | 500 | Superfine (Red) | |||||
| P1000 | F400 | 18.3 ± 1.0 | |||||
| 16.0 | 600 | ||||||
| P1200 | 15.3 ± 1.0 | Grey | |||||
| P1500 | F500 | 12.6 ± 1.0 | |||||
| 12.2 | 800 | Ultrafine (Blue) | |||||
| P2000 | F600 | 10.3 ± 0.8 | |||||
| 9.2 | 1000 | Blue | |||||
| P2500 | 8.4 ± 0.5 | ||||||
| 6.5 | 1200 | Microfine (Green) | |||||
| 3 | 1500 | Pink | |||||
| 2 | Mint | ||||||
| 1 | 2000 | Light Green | |||||