This chapter familiarizes readers with the design, configuration, and function of tooling and dies used to extrude aluminum alloys. It discuses basic design considerations, including the geometry, location, and orientation of die openings; allowances for thermal shrinkage, stretching, and deflection; and the length and profile of bearing surfaces. It outlines the steps and processes involved in die making, describes the selection and treatment of die materials, and examines the factors that influence friction and wear. It also discusses the general procedures for on-site die correction.