Blank used for manufacturing single-headed piston, and method of producing the blank

摘要

Method of producing a blank for manufacturing a single-headed piston having a head portion and a neck portion formed integrally with the head portion, for engagement with a drive member, the method including: a step of manufacturing a body member including a twin neck section and two cylindrical hollow head sections formed integrally with the twin neck section so as to extend from opposite ends of the twin neck section, the twin neck section consisting of two portions which are mutually integrally formed in series with each other and which correspond to the neck portions of respective two single-headed pistons, each hollow head section being open at at least one of opposite ends thereof which is remote from the twin neck section; a step of manufacturing two closing members each for closing an open end of the corresponding hollow head section; and a step of fixing each closing member to the body member, so as to close the open end of the corresponding hollow head section.