
Needle roller bearings utilize cylindrical rollers with a length-to-diameter ratio exceeding 4:1. This “needle-like” geometry enables exceptional radial load capacity within extremely compact cross-sections, providing superior space efficiency compared to ball bearings of equivalent dimensions.
| ISO | HK0408 | |
| Raceway diameter inner ring | F | 4 mm |
| Outside diameter | D | 8 mm |
| Width | B | 8 mm |
| Basic dynamic load rating | C | 0.85 kN |
| Basic static load rating | C0 | 0.63 kN |
| Limiting speed | 19700 r/min | |
| Mass bearing | 0.002 kg | |
Key components include: