The feed direction of the carbide milling cutter relative to the workpiece and the rotation direction of the milling cutter mainly include the following two milling methods:

The first is down milling. The rotation direction of the milling cutter is the same as the feeding direction of the cutting. When the cutting starts, the milling cutter bites the workpiece and cuts off the last chips.

The second is up-cut milling. The rotation direction of the milling cutter is opposite to the feeding direction of the cutting. The milling cutter must slip on the workpiece for a period before starting to cut, starting with the cutting thickness of zero, and reaching the cutting thickness at the end of the cutting. maximum.

During down milling, the cutting force presses the workpiece toward the worktable, and during up milling, the cutting force causes the workpiece to leave the worktable. Since the cutting effect of down milling is the best, down milling is usually the first choice. Only when there is a thread clearance problem on the machine tool or a problem that cannot be solved by down milling, up milling is considered.

Every time the carbide milling insert enters the cutting, the cutting edge is subjected to an impact load, and the magnitude of the load depends on the cross section of the chip, the workpiece material and the type of cutting. Ideally, the diameter of the milling cutter should be larger than the width of the workpiece, and the axis of the milling cutter should always be slightly away from the centerline of the workpiece. When the tool is placed directly on the cutting center, it is very easy to produce burrs. The direction of the radial cutting force will constantly change as the cutting edge enters and exits the cut, the machine tool spindle may vibrate and be damaged, the insert may chip and the machined surface will be very rough, the carbide milling cutter is slightly off center, the cutting force direction will be No more fluctuations, the milling cutter will receive a preload.