Abstract: A screw driver comprising a torque responsive clutch for determining the final tightening torque and an output spindle connected to a forwardly extending screw bit. The spindle is axially displaceable from a forward rest position to an intermediate tightening position and a rear position in which dogs on the spindle engage dogs on the driving part of the clutch for inactivation of the clutch. The spindle, which is spring-biased toward its normal tightening and rest positions, is permitted to reoccupy its normal tightening position during the final tightening sequence in that a stud element on the screw driver housing is arranged to abut against the screw landing surface, thereby automatically preventing the screw driver housing and the clutch from following the spindle and screw bit to their final positions and ensuring reactivation of the clutch.