Method of making cylindrical work pieces of progressively increasing diameters, and device for carrying out the method.

摘要

A method for making a cylindrical work piece of progressively increasing internal and/or external diameters, by contracting down and drawing down through dies, in which a support-nose, substantially perpendicular to the axis of the work piece, is formed on the internal periphery and in the vicinity of the front end of the blank to be drawn down, on which support-nose is exerted the thrust of the mandrel, and a device for carrying out the method. The support-nose is formed by contracting down the end of the blank (9) on the end (10) of the mandrel (2) by pushing the blank and the mandrel held together in axial displacement through one or more contracting-down dies (1). It is then possible to contract down and/or draw down the blank on the same mandrel. <IMAGE>