| Grade | VOWS Ball Dia variation |
△sph Deviation From Spherical Form |
Surface Roughness |
| No Larger Than | |||
| μm | |||
| 3 | 0.08 | 0.08 | 0.010 |
| 5 | 0.13 | 0.13 | 0.014 |
| 10 | 0.25 | 0.25 | 0.020 |
| 16 | 0.4 | 0.4 | 0.025 |
| 20 | 0.5 | 0.5 | 0.032 |
| 28 | 07 | 0.7 | 0.040 |
| 40 | 1 | l | 0.050 |
| 60 | 1.5 | 1.5 | 0.060 |
| 100 | 2.5 | 2.5 | 0.080 |
| 200 | 5 | 5 | 0 150 |
