This research is focused on the investigation of robust surface interrogation tools which can support the planning and programming of 5-axis die/mold surface machining. Surface curvature information is evaluated to determine optimal tool orientation for 5-axis machining. A method for calculating machining strip width is proposed for 5-axis cutter path generation. This paper is focused on the development of computational geometry techniques and their application to design, analysis, and manufacturing automation. The proposed planning and programming methodology consists of two steps: 1) machining strip width evaluation, and 2) optimum tool orientation for 5-axis machining. This proposed research can be used to improve the quality of 5-axis die/mold machining.