The abrasive-wear resistance and the lifetime of tribologically stressed free-formed surfaces of forming tools can be increased by thermally sprayed tungsten carbide coatings. In order to improve the surface quality and the shape accuracy, the workpieces must be machined prior to industrial application. A suitable machining process is NC grinding on five-axis machining centres using abrasive mounted points. However, the high hardness of the applied coatings and the small diameter of the utilized tools pose a great challenge for the process design. In order to optimize the grinding process and predict the resulting surface topography, a geometric-kinematic simulation based on the modelling of individual grains using Constructive Solid Geometry techniques was developed. In this paper, the results of fundamental investigations on grinding tungsten carbide coatings and the developed process simulation are presented.