Abstract: A two-speed gear box for handheld electric drills and the like has the movable parts associated with gear changing on or associated with a lay shaft. Gear changing is preferably effected by moving a pair of dogs, slidably mounted in holes through a lay shaft gear, to drivingly engage in either of two dog clutch members on the lay shaft. A thin flexible arm, preferably including a ring around the lay shaft, mounted in cantilever fashion from a movable base effects movement of the dogs. Should the dogs not be in proper register with a respective dog clutch member when changing speed, then the arm flexes and urges the dogs into driving engagement when proper register occurs. A family of two-speed drills having different specialized functions, e.g. a drill, a hammer drill, a screwdriver/drill, a screwdriver, etc., can be produced with the maximum parts in common enabling greater manufacturing flexibility and lower cost of manufacturing the family.