AbstractHobbing is the most widely employed cutting method for producing cylindrical gears, splines, and so on. However, because the wearing of the hob cutters always reduces their accuracy, the tooth faces on the hob gashes must be reground to ensure the accuracy of the machined gear and prolong the cutter’s lifetime. In practice, the deviations of the ground tooth face of hob gashes are caused by machine error. This paper thus proposes a high-order flank correction method based on the degrees of freedom in the five-axis computer numerical control (CNC) hob sharpening machine. The behavior of each axle of the grinding machine is described by high-order polynomials, and the sensitivity of the polynomial coefficient is derived based on the topographic normal deviation on the tooth face. The ground tooth face can then be approximated to the theoretical tooth face by adjusting the coefficients of the polynomials based on their sensitivity. We demonstrate the validity of this flank correction method numerical...