DIRECT OR INDIRECT METAL PIPE EXTRUSION PROCESS, MANDREL FOR EXTRUDING METAL PIPES, METAL PIPE EXTRUDER AND EXTRUDED METAL PIPE

摘要

If a mandrel for extruding metal pipes, having two axially offset pressing surfaces with different radial embossing and having a transition region between these two pressing surfaces has a support surface in the transition region then the negative effect of narrowing, which arises owing to the mandrel shifting from a first pressing position, in which the first of the two pressing surfaces interacts with a die, to a second pressing position, in which the second pressing surface interacts with the die, can be minimized.