The machine itself consists of a radial arm joint to a tilting arm balanced by means of a pneumatic spring. The head member and the electric motor find themselves at the end of the tilitng arm and is to adapt to always move at right angle with respect to its working area. The "high frequency" is regulated by menas a variator board located in the "electronic box casing". The turning motor and the optional automatic lubrication control are adjustable by menas of the buttons being located over the "radial arm". The speed can be thus adapted to every thread type. The tapholders are fixed to the motor by means of a quick cahnge, and taps fixes directly to the tapholders.