When milling cutter is cutting the plane and side of the workpiece, can use different cutting tool rail style, called cutting pipe. There are nine kinds of cutting pipes, as follows:

(1) CNC milling machine reciprocating cutting pipeline. The distance between the two parallel cutting tool rails is one step. The head of a cutting tool rail and the tail of another cutting tool rail are connected by a step-in rail. The step-in rail and the cutting tool rail are at the same level, and there is only one segment of the whole cutting tool rail that is close to the cutting tool rail, the feed tool rail and the return tool rail. Reciprocating cutting pipe has both direct milling and reverse milling.

Each track of unidirectional profile cutting tool track has a section of approach track, feed track and return track. The return point of the former cutting tool track is connected with the starting point of the latter cutting tool track with a fast moving tool. The approach track, feed track, return track and fast moving track are not on the same level. The two short cutting tool rails make up for the lack of cutting tool rails at one end of reciprocating cutting pipe and at both ends of one-way cutting pipe.

(2) CNC milling machine following the peripheral cutting pipeline. The cutting pipe following the periphery is the tool rail of the inner ring of the outer loop, and the shape of the tool rail of the outermost loop is consistent with the shape of the boundary contour of the workpiece. The distance between two adjacent tool rails is one step. The step feed rails and cutting tool rails between the two loops are in the same level. All the tool rails at the same level have only one section of approach tool rails, feed tool rails and return tool rails. There are two directions of cutting data: one is to cut from the large circular tool track (outside) to the small circular tool track (inside); The other is to cut from a small circular (inside) to a large circular (outside).

(3) CNC milling machine cycloid cutting pipeline. Cycloidal cutting pipe is the tool movement to the narrow concave Angle area, the lateral tool depth suddenly become deep, in order to prevent the knife and break the knife can be used cycloidal cutting pipe.

(4) CNC milling machine one-way cutting pipeline. The unidirectional cutting pipe is the tool cutting in a straight line from one end to the other, and then lifting the tool back, at a step interval, and then cutting from one end to the other, each cutting tool rail in the same direction. Each cutting tool track has a section of approach tool track, feed tool track and return tool track. There is only one type of unidirectional cutting pipe.

(5) CNC milling machine one-way contour cutting pipeline. There are three sections of the one-way profile cutting tool rail, long straight sections are parallel to each other, the cutting direction is the same, and the spacing is one step. There is a short cutting tool rail at each end of the long cutting section. The shape of the short cutting tool rail is the same as the shape of the workpiece's side profile, which can be a straight line or a curve. The span of the short cutting tool rail is one step.

(6) CNC milling machine following the workpiece cutting pipeline. Following the workpiece cutting pipe to cut both cavity and core of the workpiece to choose to follow the workpiece cutting pipe. The tool rails of the cutting pipeline following the workpiece are also loops of closed tool rails, but the shape of the innermost tool rails of the cutting core is consistent with the contour of the core, the shape of the outermost tool rails of the cutting cavity is consistent with the contour of the cutting cavity, and the tool rails at the intersection are self-determined by UG CAM system. The distance between two adjacent tool rails is one step. The step feed rails and cutting tool rails between the two loops are in the same level. All the tool rails at the same level have only one section of approach tool rails, feed tool rails and return tool rails. Following the workpiece cutting pipe has both forward milling and reverse milling, cutting cavity with forward milling, cutting core with reverse milling.

(7) CNC milling machine profile cutting pipeline. Profile cutting pipe is used for side wall semi - finishing and finishing. After rough machining, a small amount of residual is left to use contour cutting pipeline to carry out lateral single layer, axial multi-layer semi-finishing and finishing on the side wall.

(8) CNC milling machine standard drive cutting pipeline. The function of the standard drive cutting pipe is the same as that of the contour cutting pipe. The tool rails of the standard drive cutting pipe can be crossed.

(9) CNC milling machine mixed cutting pipeline. A workpiece after the rough machining produced several cutting areas, these areas with several kinds of cutting pipe cutting, known as mixed cutting pipe. Mixed cutting pipe is reciprocating, following the periphery and following the workpiece three kinds of cutting pipe are used in a different cutting area of the workpiece.