| NSK 2304K Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| RHP 2304 Bearing | 20 | 52 | 21 | RHP | Self-aligning Ball Bearings |
| KOYO 2304 Bearing | 20 | 52 | 21 | KOYO | Self-aligning Ball Bearings |
| NSK NJ2304 Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| SNR 2304 Bearing | 20 | 52 | 21 | SNR | Self-aligning Ball Bearings |
| FLT NUP2304 Bearing | 20 | 52 | 21 | FLT | Cylindrical Roller Bearings |
| RHP NU 2304 Bearing | 20 | 52 | 21 | RHP | Cylindrical Roller Bearings |
| FAG NJ 2211 +HJ 2212 Bearing | 20 | 52 | 21 | FAG | Cylindrical Roller Bearings |
| RIV NU 2304 Bearing | 20 | 52 | 21 | RIV | Cylindrical Roller Bearings |