This is the genuine unit to work in any position in space therewith always maintaining the perpendicularity to the desired plane irrespective of the arm position. The machine consists of a radial arm supporting both articulated arms that can be regulated by means of the regulating valves. The multiposition head is a double swivel joint device allowing to lock and unlock both its swivel pins to thus position the head and keep it quite blocked in order to thus operate in any position in space. The head mechanism is formed by a cam system with an equaliser and disc springs applying a load of 1,000 Kg to two cone sets locking both pins. The radial arm incorporates a chain drive, which is activated or deactivated by means of a face-toothed coupling half according to the intended working position. The machine incorporates an air servicing unit (filter + regulator + lubricator) for the correct operation of the motor. The modular system consisting in a series of 7 quick-change modules (reducers) is provided for coupling to said motor. As a result of this 7 output speeds (90, 170, 300, 550, 750, 1050 and 2100 rpm) are available thus allowing to adapt the tap speed to every type of thread. The modular system admits the quick-change tap holders with or without safety clutch depending on the intended job (blind or through holes). Threading capacity from M3 up to M2 to M24 (M27).