Abstract: A spiral tool path is formed by determining a plurality of relatively low-curvature nested contours that are internal to the boundary of the pocket to be formed, and spiraling between the contours. The spiral tool path includes an orbit that extends from proximate a first one of the contours that extends around a center of the pocket to be formed to proximate a second one of the contours that also extends around the center. The orbit is arranged so that as a ray originating from proximate the center pivots about the center to travel in a first direction along the entire orbit, for a section of the ray extending between the first and second contours, the percentage of the section that extends between the orbit and the first contour continually decreases and the percentage of the section that extend between the orbit and the second contour continually increases.