Abstract: A rotary impact tool of the type for applying a torque force and having an input, output and spring-accelerated inertia members and journaled on each other for rotative movement relative to each other and a cam connected for conjoined rotation with the input member and for actuating juxtaposed pawls carried by the inertia member into and out impact engagement with circumferentially spaced teeth on the output member for driving the latter, the cam being so shaped and positioned relative to the input inertia and output members to coact with the pawls so as to provide impact engagement of the pawls with the spaced teeth of the output member in both directions of rotation. In another aspect of the invention, the cam is capable of angular adjustment relative to the input and inertia members to predetermined positions to achieve impact driving forces of different magnitude or to apply impact driving force in one direction or the opposite direction of rotation.