| NACHI NJ 2304 Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| NSK 2304K Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| NSK NJ2304E+HJ2304E Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| KOYO NUP 2304 R Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| SKF NJ2304E Bearing | 20 | 52 | 21 | SKF | Cylindrical Roller Bearings |
| NSK NSKNU2304ECP Bearing | 20 | 52 | 21 | NSK | Cylindrical Roller Bearings |
| NSK NSK2304E-2RS1TN9 Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| SKF NJ 2306 E +HJ 2308 E Bearing | 20 | 52 | 21 | SKF | Cylindrical Roller Bearings |
| NACHI NJ2304 Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |