When the surface structure is relatively simple, and the curvature in a direction parallel to the axis, similar to Fig, they may be 0 degrees and 90 degrees using the tool path, i.e., along the path of the tool path parallel to the path direction of the curvature of the surface; in most cases under constitute more complex surfaces, the surface roughness of the surface in some less demanding situations, we will adopt a more eclectic path angle of -45 degrees, so you can make the machined surface under the premise of efficiency as possible to reach the surface quality; more stringent requirements on the surface roughness of the mold processing, we can separate the different surface processing to take advantage of a variety of path pattern - parallel lines cut, contour shape, surface flow lines, radial radiation, etc., to achieve best surface roughness