公开(公告)号：US10906077B2

公开(公告)日：2021-02-02

申请号：US15638535

申请日：2017-06-30

Applicant: SMS group GmbH

Inventor： Uwe Muschalik ,  Jens Magenheimer ,  Anna Rott ,  Koos van Putten

IPC: B21C25/04 ,  B21C23/08 ,  B21C23/21 ,  B21C25/08 ,  B21C23/20

Abstract: If a mandrel for extruding metal pipes, having two axially offset pressing surfaces with different radial characteristics 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.