A rotary tool, such as an impact wrench, operable in a forward mode and a reverse mode. The rotary tool includes a housing (12) having a forward end and supporting a motor. The motor has a motor shaft (24) extending axially through the housing and defining an axis. The rotary tool also include a frame (34) supported in the housing and being rotatable relative to the housing about the axis, an output shaft (92) supported in the forward end of the housing and rotatable about the axis, and a hammer (48,48') pivotably coupled to the frame and defining a central aperture (62). The hammer has a first jaw and a second jaw (66,68) extending into the central aperture. The first jaw and the second jaw are non-symmetrical.