Method for forming threadings in a bushing which is used to secure a hose therein

摘要

A method is provided for forming threadings in a bushing and includes (a) providing a die; (b) extruding a tubular bushing made of metallic material into the die; (c) providing a punch member to punch into the bushing to form a first threading therein; (d) pressing down the bushing along the die and again providing the puncher member to punch into the bushing to form a second threading therein; and (e) repeating the step (d) until a plurality of predetermined threadings are formed in the bushing.