638ZZ1
| d | 8 | mm | Bore diameter |
| D | 28 | mm | Outside diameter |
| B | 9 | mm | Width |
| r1 (min.) | 0.3 | mm | Chamfer dimension |
| Cr | 5050 | N | Basic dynamic load rating |
| C0r | 1970 | N | Basic static load rating |
| Grease | 28000 | min-1 | Grease lubrication |
| db (max.) | 12.8 | mm | Diameter of shaft abutment |
| Db (max.) | 22.6 | mm | Diameter of housing abutment |
| rb (max.) | 0.3 | mm | Radius of shaft or housing fillet |
| (approx.) | 0.0286 | kg |