|Centring, Drilling and Counterboring / Countersinking - Course: Techniques for machining of material. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 22 p.)|
Counterboring/countersinking with counterbore/countersink and turning tool is a finishing operation on the internal surface of internally premachined rotationally symmetrical parts. Counterboring/countersinking on the lathe with special counter-bores/countersinks is of minor importance. Essential advantages are achieved by counterboring/countersinking on the lathe with the turning tool which results in higher surface finish and dimensional accuracy with less tooling costs.
- The cutting is done by turning tools using counterboring/countersinking tools (see Fig. 5, 6, 14 in section 2).
- Combination tools (piloted counterbore, step countersink, combination countersink) can be economically used since several operations are combined into a single one.
- Counterbores/countersinks with straight shank are chucked in a drill chuck; counterbores/countersinks with taper shank are inserted in the taper hole of the sleeve.
- When working with the counterbore/countersink, a relatively low speed rate is to be selected to avoid chatter marks (scratches, grooves).
- During counterboring/countersinking of parts made of steel, cast steel, red brass or light metal, coolants or lubricants are to be used to improve the surface finish.
Chips must never be removed by hand - danger of accidents!
What are the advantages of step countersinks and combination
Why is the counterboring/countersinking technique on the lathe
with special counterbores/countersinks of minor