Technology for milling selected portions of a workpiece by a cutting tool of a numerical control machine is described. The described technology provides methods and apparatuses for milling areas of a part so that more aggressive machining parameters can be used in the toolpath, thereby resulting in reduced machining time and load. The technology creates a series of toolpath contours where arcs in the toolpath contours are non-concentric with arcs in other toolpath contours. The selected portions of the workpiece are milled by moving the cutting tool in accordance with the toolpath.