A method of generating 'optimal' cutter-location data for 5-axis NC contour milling from given cutter-contact data is presented in the paper. The cutter-location data-optimization problem is formulated as a 2D constrained minimization problem. The cutter orientation angles consisting of the tilt angle alpha and yaw angle beta are used as decision variables. An analytic expression for approximate cusp heights is derived as a function of alpha, beta (for a given path interval) to be used as a measure of optimality. The proposed optimization scheme has been successfully applied in the 5-axis face milling of large marine propellers.