An approximate model has been developed to improve our understanding of flow control at the exit of an extrusion die. This paper deals with the design of traditional die flow correctors used in flat-faced aluminum extrusion dies. The numerical model uses the finite-element method combined with techniques of mathematical programming. Analytical sensitivities have been developed from the discretized finite-element equations in order to compute the necessary derivatives during optimization. The model includes thermal effects, and the extruded material is assumed to be strain-rate and temperature dependent.