
| Driling, Countersinking and Counterboring - Course: Technique for Manual Working of Materials. Trainees' Handbook of Lessons |
Workpieces roust be clamped in such a way that they cannot fling around or be drawn up.
Small workpieces can be held by clamp dogs or hand vices on a support if only a small rotary power is to be expected (small bore holes).

Larger workpieces are safely clamped in the machine vice that can be equipped with straight or prismatic jaws.
Cylindrical parts may also be clamped in the drilling v-block

Very big parts must be clamped on the machine table directly.
For this purpose, clamps and locking screws as well as other auxiliary means are required.
For series and mass production, drill jigs are used.

1 - Clamps
2 - Step block
3 - Locking screw
4 - Supporting hexagon (fixed at the clamp)
5 - Workpiece
6 - Machine table