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close this bookThread Cutting by Dies and Taps - Course: Techniques for machining of material. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 20 p.)
View the document(introduction...)
View the document1. Purpose and importance of thread cutting by dies and taps
View the document2. Construction and types of dies and taps
View the document3. Preparations for thread cutting by dies and taps
View the document4. Thread cutting by dies on simple cylindrical workpieces
View the document5. Thread cutting by dies on recessed cylindrical workplaces
View the document6. Thread cutting by taps on through holes
View the document7. Thread cutting by taps on blind holes
View the documentAppendix 1

6. Thread cutting by taps on through holes

Internal threads are produced by thread cutting by using taps. The workpiece surfaces are processed by means of bores.

- Work is made in the chuck.

- The workpieces are clamped in the extended chuck jaws in order to guarantee true running and top surface quality as the parts have generally already been processed.

- The tap wrench is positioned on the square of the tap.

- The tap is positioned by means of the tailstock tip which is aligned to the centring of the tap.

Figure 18. Positioning the tap

1 tap, 2 tap wrench, 3 tailstock quill, 4 workpiece

- The tap wrench holder is positioned on a surface clamped into the tool holder.

- Generally speaking, the machine tap is used (economical mode of operation).

- Turn back the tap several times to remove the chips and clean the chip grooves.

- Ensure proper cooling and lubrication.

- Turn back the tap by hand upon completing the work sequence.

- The thread is checked by means of a thread ring mandrel.

Figure 19. Normal thread ring mandrel

1 thread mandrel for minor diameter

What must be heeded when thread cutting by taps?