- Features
| D51 Geometry - The quiet one |
| Ant-vibration geometry |
| For tools with extended tool projection |
| 0.08 to 0.2 mm cutting edge tolerance |
| 0.05 to 0.15 mm inscribed circle tolerance |
| +/-0.13 mm thickness tolerance |
| 4 cutting edges |
| 40 to 60 deg double countersink hole |