This paper addresses the influence of design on the performance of Equal-channel Angular Pressing dies, of which the important geometric parameters are the internal channel angle (Ф) and the curvature radii at this point. The investigation consists of FEM analysis (computational simulation) of the effect on die performance of the independent variation of the outer and inner curvature radii at the channels ́ intersection, plus the corresponding experimental validation (physical simulation). Using a Pb-62%Sn alloy, twelve R-r combinations were simulated and tested, keeping constant the Ф angle. Results indicated the best R-r combinations in terms of equivalent deformation level and homogeneity, together with the optimization of pressing forces.