US Patent 7543366 Method for producing wrench socket

A method for producing a wrench socket includes forging a metal blank to form a socket. An end of the socket includes an engaging hole for coupling with a wrench and an outer periphery surrounding the engaging hole. A support rod is inserted into the engaging hole of the socket. The support rod received in the engaging hole has a shape corresponding to that of the engaging hole. The outer periphery of the end of the socket is pressed to form size indicia on the outer periphery of the end of the socket. Surface treatment is carried out on the socket after the support rod is removed from the engaging hole of the socket.