| Bearing Number | Principal dimensions | |||
| d (mm) | d (in) | D (mm) | D (in) | |
| 31308 | 40 | 1.576 | 90 | 3.546 | 32308 | 40 | 1.576 | 90 | 3.546 |
| 30308 | 40 | 1.576 | 90 | 3.546 | 30208 | 40 | 1.576 | 80 | 3.152 |
| 32309 | 45 | 1.773 | 100 | 3.94 | 30309 | 45 | 1.773 | 100 | 3.94 |
| 30209 | 45 | 1.773 | 85 | 3.349 | 33210 | 50 | 1.97 | 90 | 3.546 |
| 31310 | 50 | 1.97 | 110 | 4.334 | 32310 | 50 | 1.97 | 110 | 4.334 |
| 30310 | 50 | 1.97 | 110 | 4.334 | 30210 | 50 | 1.97 | 90 | 3.546 |