Quality Markings
The producer of the grinding wheel marks the wheels with a code. The code consists of letters and digits and tells the grain type, grit size, wheel hardness, structure and the bond.
Example: 10 A 20 – L 3 B 2
| 10 A Abrasive Grain | 20 Grit Size | L Grade | 3 Structure | B 2 Bond Type |
|---|---|---|---|---|
| 10 A 15 A 51 A 50 A 514 A 54 A 156 A 56 A 70 C 716 C 79 C 80 C 70 CP | Very coarse 8 10 12 14 Coarse 16 20 24 30 36 Medium 46 54 60 70 80 90 Fine 100 120 150 180 220 | Extremely Soft A B C D Very Soft E F G Soft H I J Medium K L M Hard N O P Q Very Hard R S T Extremely Hard U V | Dence 0 1 2 3 Normal 4 5 6 7 8 9 Porous 10 11 12 | V: Vitrified B: Resinoid E: Shellac R: Rubber |
Grain Qualities
→ Grain Selection Chart
| 10 A | Aluminium Oxide |
| 20 A | High Quality Aluminium Oxide (light brown) |
| 30 A | High Quality Aluminium Oxide (pink) |
| 40 A | Sintered Aluminium Oxide (white) |
| 50 A | High Quality Aluminium Oxide (white) |
| 60 A | Zirconium Corundum |
| 70 C | Black Silicon Carbide |
| 80 C | Green Silicon Carbide |
| P | Hollow ball grain (white) |
| 15 A, 51 A, 514 A, 156 A, 70 CP | Combinations of grains |