Method and the device in order on the hollow metal work piece to form the outside screw mountain with non cutting

摘要

A method for the non-cutting production of an outer thread on hollow metal work pieces for use as hollow screws, hollow shafts, threaded sleeves or fittings as stable connecting or fastening elements. The method is particularly suited for thin-walled work pieces and a device is provided for carrying out the method. Within a multistage press formed with a displaceable carriage and a stationary work piece carrier unit, a wire or hollow tube section forming the base material is reshaped in one or more reshaping stages I to V into a finished hollow blank. In the multistage press, the pre-fabricated hollow blank is inserted in a further stage VI into a multipart split tool with a cavity having an inside wall that is provided with a negative of the thread to be formed. In the closed state of the split tool, at least one mandrel is inserted into the central opening of the blank and the blank is widened, wherein the contours of the threaded profile is filled by a radial material flow and subsequently the finished work piece is removed.