Wrench for tightening or loosening bolt and nut, has restraint which extends on each facet of wall of head space without covering any corner between adjacent facets

摘要

A head (11) defines a space (12) for receiving the head of a bolt, a nut, or a tool e.g. screw driver. The wall of the space comprises multiple facets (14). A restraint (15) extends on each facet without covering any corner (13) between adjacent facets.