In this paper, we describe the mechanisms responsible for the forming of rectangular bars and tubes extruded through inclined dies by numerical simulations and experiments. We carried out simulations and experiments of rectangular bars and tubes at various exit positions and extrusion ratios. The calculated trend of curvature showed good agreement with experimental results. From this reason, the validity of the numerical simulation was concluded. Curvature generation mechanisms were elucidated on the bases of simulation outputs related to the distributions of the material exit velocity and dead metal area. The turn direction differs according to the difference in exit position and the curvature increases with extrusion ratio as observed from the analytical results. The generation of dead metal area and the configuration of the container used affect the curvatures of curved rectangular bars and tubes.
