Cold working procedure for forming hollow bodies - with either a top or central shoulder, by forming rough cast, inversely extruding into die and punching

摘要

In the first part of the procedure a rough cast is made consisting of a hollow piece with a shoulder at one end, this rough cast being made from a metal billet which is extruded inversely into a cylindrical muff with a bottom piece, the bottom then being cut off and the billet annealed and phosphated. The billet is then extruded directly to form the rough cast. In the second part of the procedure the rough cast is extruded inversely into a hollow body with either a central or top shoulder using a die which has a fixed punch fitting inside the bore of the rough cast and a punching ring which has an exterior diameter equal to the interior diameter of the die and an interior dia. equal to the required exterior diameter of the body to be extruded.