Roughing tap
Straight fluted taps made undersize to reduce the load on the finishing tap and particularly for difficult tapping operations.
Recommended for use when tapping steels o close tolerance fits as required, reducing wear on the finishing tap.
Finishing tap
Hａnd or machine tapping for through holes and blind holes where ample chip clearance is available.
The lead chamfer permits easier starting and requires less tapping torque than bottoming taps.
Bottoming tap
Used for tapping blind holes when maximum full form threads are required in minimum depth holes.
Spiral flute tap
Tap designed with spiral flutes in the same “hand” as the thread. This directs the swarf backwards out of the hole. Recommended for blind or deep hole applications in soft (eg. Aluminium) materials.
Due to the suitability blind hole tapping the lead chamfer is normally that of a bottoming tap.
Spiral point tap
Designed primarily as a machine tap for tapping through holes.
The Spiral Point is formed in the lead teeth at an angle to the tap axis. The swarf, due to the cutting action, is pushed forwards ahead of the tap.
The flutes of the spiral point tap serve only to deliver coolant to the cutting edges, therefore much shallower flutes are used. Subsequently the tap has greater strength and makes precise tapping possible.
Not recommended on abrasive materials.
