FEPA - ISO 6106-2005 standard, issued according to FEPA (Federation of European Producers of Abrasives) recommendations
MESH - ANSI B74.16-2002 American standard
DIN - DIN 848-65 German standard
GRIT SIZE CLASS - It is an indicative description that refers to precision grinding
| FEPA | U.S. | MESH | DIN | GRIT SIZE CLASS | ||
|---|---|---|---|---|---|---|
| 7 | 2500 | - | 7 | MICRON | ||
| 10 | 2000 | - | ||||
| 12 | 1500 | - | ||||
| 15 | 1200 | - | 15 | |||
| 20 | 1000 | - | 15 | |||
| 25 | 800 | - | 15 | |||
| 30 | 600 | 500/600 | 30 | VERY FINE | ||
| 35 | 500 | 400/600 | ||||
| 46 | 400 | 325/400 | 35 | |||
| 54 | 325 | 270/325 |
|
FINE | ||
| 64 | 280 | 230/270 |
|
|||
| 76 | 220 | 200/230 | 85 | |||
| 91 | 180 | 170/200 | ||||
| 107 | 150 | 140/170 |
|
MEDIUM | ||
| 126 | 120 | 120/140 | ||||
| 151 | 100 | 100/120 |
|
LARGE | ||
| 181 | 80 | 80/100 |
|
|||
| 252 | 60 | 60/80 | 200/250 280 |
VERY LARGE | ||
| 301 | 50 | 50/60 | ||||
| 427 | 40 | 40/50 | 300 | SPECIAL USE | ||
| 602 | 30 | 30/40 | ||||
| 852 | 20 | 20/30 | ||||
| 1182 | 16 | 16/20 |
Just as an indication, you can find right here a table of the various types of roughness that can be reached on carbide surface grinding (cutting speed approx. 24 m/sec - table speed 15 m/min) coolant: water-based emulsion.
| GRIT | |||||||
|---|---|---|---|---|---|---|---|
| FEPA | 7 | 15 | 54 | 76 | 107 | 181 | 602 |
| US | 2500 | 1200 | 325 | 220 | 150 | 80 | 30 |
| ROUGHNESS | |||||||
| Ra(μ) | 0.05 | 0.10 | 0.20 | 0.40 | 0.80 | 1.60 | 3.20 |
| CLA(μ) | 2 | 4 | 8 | 16 | 32 | 64 | 125 |
| Swiss | N2 | N3 | N4 | N5 | N6 | N7 | N8 |
The abrasive concentration is expressed in carats/cc. It stands for the ratio between its weight and the volume of the abrasive conglomerate; the weight of the grit cladding, if present, is not taken into account.
| Concentration | 35 | 45 | 50 | 68 | 75 | 90 | 100 | 125 | 150 |
|---|---|---|---|---|---|---|---|---|---|
| Ct/cm3 | 1.5 | 2 | 2.2 | 3 | 3.3 | 4 | 4.4 | 5.6 | 6.6 |