| NSK 2304 Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| NACHI NJ 2304 +HJ 2304 Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| KOYO 2304 Bearing | 20 | 52 | 21 | KOYO | Self-aligning Ball Bearings |
| SNR 2304 Bearing | 20 | 52 | 21 | SNR | Self-aligning Ball Bearings |
| STEYR NUP2304 Bearing | 20 | 52 | 21 | STEYR | Cylindrical Roller Bearings |
| KOYO 2304K Bearing | 20 | 52 | 21 | KOYO | Self-aligning Ball Bearings |
| NSK 2304 K Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| STEYR 2304 Bearing | 20 | 52 | 21 | STEYR | Self-aligning Ball Bearings |
| SKF 2304TN Bearing | 20 | 52 | 21 | SKF | Self-aligning Ball Bearings |