the invention discloses a power tool for screwing or drilling having a motor for driving a drive shaft , a controller for controlling the power tool , a motor switch for switching the motor on and off , switch for reversing the power tool between clockwise and counter - clockwise rotation , and vice versa , and a timer that permits reversal of the power tool between clockwise / counter - clockwise rotation , and vice versa , within a predefined period of time between actuation of the switch for clockwise / counter - clockwise rotation and for operation of the motor switch to start the power tool .