In this paper, finite element analysis of an elongation process after the Mannesmann roll piercing process during seamless pipe manufacturing is conducted using a rigid-viscoplastic finite element method. The importance of the process is emphasized with a typical shape defect occurring in the elongation process. Basic approaches with an analysis model are presented together with an example found in the related industries. The predictions of contact area between material and guide shoe are compared with experiments to reveal the validity of the approach.