Abstract: A socket wrench modified by the addition of auxiliary gripper ribs to either prevent bolt head stripper action or to minimize the adverse effects of such stripper action. In one case the bolt head is initially formed to have grooves in its side surfaces mated to gripper ribs on the wrench. In an alternate arrangement the gripper ribs are designed as cutter devices to form grooves in the bolt side surfaces by the application of a hammering force on the wrench.