A power tool includes a housing, a motor supported in the housing, a chuck assembly having a chuck body rotatable about a central axis in response to torque received from the motor, and a plurality of jaws supported in the chuck body. Each of the jaws includes a front portion operable to grasp a tool element and a rear portion positioned outside the chuck body. The power tool also includes a hammer mechanism operable to impart movement to the chuck assembly, in a direction parallel to the central axis, during rotation of the chuck assembly about the central axis.