| KOYO NJ2304R+HJ2304R Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| FLT NUP 2304 Bearing | 20 | 52 | 21 | FLT | Cylindrical Roller Bearings |
| SKF 2304 Bearing | 20 | 52 | 21 | SKF | Self-aligning Ball Bearings |
| SKF NUP 2304 E CP* Bearing | 20 | 52 | 21 | SKF | Cylindrical Roller Bearings |
| NSK 2304 K Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| NACHI NJ 2304 E Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| NACHI NJ 2304 +HJ 2304 Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| NSK NU 2304 E Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| SKF NJ2304E+HJ2304E Bearing | 20 | 52 | 21 | SKF | Cylindrical Roller Bearings |
| FAG NJ 2304 E Bearing | 20 | 52 | 21 | FAG | Cylindrical Roller Bearings |