| KOYO NU2304 Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| SKF 2304 E-2RS1 Bearing | 20 | 52 | 21 | SKF | Self-aligning Ball Bearings |
| NACHI NJ 2304 E +HJ 2304 E Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| MAC NUP2304 Bearing | 20 | 52 | 21 | MAC | Cylindrical Roller Bearings |
| NSK NUP2304E Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| NTN 2304 Bearing | 20 | 52 | 21 | NTN | Self-aligning Ball Bearings |
| STEYR NJ 2304 E Bearing | 20 | 52 | 21 | STEYR | Cylindrical Roller Bearings |
| SKF 4304ATN9 Bearing | 20 | 52 | 21 | SKF | Deep Groove Ball Bearings |
| NSK NU2304E Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| NACHI NU 2304 E Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |