Abstract: Addressing the control of the pierced billet dimensional accuracy of the tube as rolled by the retained mandrel mill, the FEA software MSC.SuperForm is adapted to develop 3-D simulation to study the corresponding relationship between the mandrel retained-speed and the pierced billet dimensional accuracy and the mandrel axial force.The study result reveals that the mandrel speed plays a critical role in affecting the in-groove uneven deformation of the metal and the stretch/push force between the rolling stands.Accordingly increasing the mandrel speed will remarkably improve the pierced billet dimensional accuracy and the stretch/push force between the stands, whereas the mandrel axial force will be increased along too.In case of the workshop operation, the mandrel speed should be determined based on a proper balance between the mandrel axial force and the pierced billet dimensional accuracy.