Abstract: A portable, handheld, power tool is operable to rotate a tap in an opening in a workpiece to form an internal thread convolution in the opening. The power tool includes a chuck which holds the tap. Left and right handles extend in opposite directions from the chuck and are connected with a housing. A motor is disposed in one of the handles and is connected with the chuck by a drive mechanism. Manual actuation of a motor control lever mounted on the one handle initiates operation of the motor. Upon operation of the motor, force is transmitted through a drive mechanism to the chuck to rotate the chuck and the tap. Upon interruption of operation of the motor, the tap may be rotated under the influence of force which is manually applied to the handles.