Method of manufacturing a blank raw material for a hose end fitting

摘要

A method of manufacturing a blank raw material for a hose end fitting includes several steps, The method includes providing a rod-shaped material having a socket end and a screw-connecting end, and forming at the socket end of the rod-shaped material a pipe-shaped socket portion and a rod-shaped nipple portion surrounded by the pipe-shaped socket portion. A flange portion is formed having a diameter larger than that of the socket portion in an intermediate portion of the rod-shaped material by fitting a second pipe-shaped mold to the screw-connecting end so as to sandwich and compress the intermediate portion between the first pipe-shaped mold and the second pipe-shaped molds A screw-connecting portion is formed at the screw-connecting end by inserting a punch in a center portion of the rod-shaped material when an external periphery of the rod-shaped material is supported by the second pipe-shaped mold. A rod-shaped nipple having a through-hole extending to a bottom surface of the screw-connecting portion is formed by fitting a pipe-shaped punch between the pipe-shaped socket portion and the rod-shaped nipple portion.