Description:
Hand taps are manufactured from HSS steel. They are used for tapping threads in open and closed holes in alloyed and non-alloyed steels up to a hardness of 800 N/mm², ductile iron and non-ferrous materials. Engraving is done in three operations.
Application:
- To cut the internal thread, first drill a core hole whose diameter is approximately one step smaller than the nominal diameter of the thread.
- Taper holes are then made 10% larger than the thread diameter to provide better feed into the bore when tapping and to prevent the first and last thread notches from being pushed outward.
- Then the taps are twisted and unscrewed in turn. The final diameter of the thread core is created by additional plastic shaping of the thread flanks.
- For a longer service life of the tools and optimal surface quality, cutting oils or other cooling lubricants are used for lubrication, because they reduce the friction between the chips and the blades of the screw drill, and thus also the necessary torque.
- With manual taps, after two turns, the drill must be turned back a third of a turn to break off the chip. This reduces the load on the drill bit, which therefore does not break as quickly.