| Factory | Number | Cross Interchange Type | Relevance |
|---|---|---|---|
| SKF | MU1921X | Direct Cross Interchange | 4 |
| ROLLWAY | U1921 | Direct Cross Interchange | 3 |
| TIMKEN | MU1921V | Direct Cross Interchange | 3 |
| FEDERAL MOGUL | MU1921V | Direct Cross Interchange | 2 |
| Precision Seals & Bearings | MU1921V | Indirect Cross Interchange | 4 |
| NDH | BU1921 | Indirect Cross Interchange | 2 |
| NSN | 3110009485796 | Indirect Cross Interchange | 2 |
| CATERPILLAR | 1M5513 | Indirect Cross Interchange | 2 |
| BOWER | MU1921V | Indirect Cross Interchange | 2 |
| BOWER | MU1921L | Indirect Cross Interchange | 2 |
| LINK BELT | MU1921X | Indirect Cross Interchange | 2 |