Points to note when using end mills

Machining center with end milling cutter mostly adopts spring clip set clip, when used in a cantilever state.

Milling process, sometimes the end milling cutter from the tool holder gradually out, or even completely fall, resulting in the phenomenon of workpiece scrap, the reason is generally because the inner hole and end milling cutter handle diameter between the oil film, resulting in insufficient clamping force. End milling cutter factory is usually coated with anti-rust oil, if the use of water-soluble cutting oil, tool holder inner hole will also be attached to a layer of fog oil film, when the handle knife clip are stored oil film, tool holder is difficult to firmly clamp the handle, end milling cutter is easy to loose and fall off. Therefore, before the end milling cutter clamping, the inner hole of the end milling cutter holder should be cleaned with cleaning fluid, dried and then clamped.

Vibration of end milling cutter due to a small gap between the end milling cutter and tool holder, so the machining process of the cutter may appear vibration phenomenon.

The vibration will make the edge of the end milling cutter cut unevenly, and the expansion of the cutting is larger than the original value, which will affect the machining accuracy of the tool life. However, when the groove width is small, it can also make the tool vibration purposefully, and obtain the required groove width by increasing the cutting expansion amount. In this case, the maximum amplitude of the end milling cutter should be limited below 0.02mm, otherwise stable cutting cannot be carried out. The lower the vibration of end milling cutter in normal machining, the better. When the tool vibration occurs, it should be considered to reduce the cutting speed and feed speed. If both of them have been reduced by 40%, there is still a large vibration, then it should be considered to reduce the amount of cutting tool. If the processing system appears resonance, the reason may be that the cutting speed is too large, the feed speed is small, the tool system rigidity is insufficient, the workpiece clamping force is not enough and the workpiece shape or workpiece clamping method and other factors caused by, at this time should be taken to adjust the cutting amount, increase the tool system stiffness, improve the feed speed and other measures. 

When the cutting point is a concave part or deep cavity, the extension of the end milling cutter should be lengthened.

If the use of long edge end milling cutter, due to the tool deflection is large, easy to produce vibration and lead to tool damage. Therefore, in the process, if only the edge near the end of the tool to participate in the cutting, it is best to choose the total length of the tool is longer than the length of the long shank end milling cutter. When the workpiece is processed with large diameter end milling cutter on horizontal numerical control machine tool, more attention should be paid to the problem of end cutting because of the large deformation caused by the dead weight of the cutter. When long edge end mills must be used, the cutting speed and feed speed must be greatly reduced.

The choice of cutting mode using straight milling is conducive to prevent damage to the blade, can improve the life of the tool.
There are two points need to pay attention to:

(1) if the use of ordinary machine tool processing, should try to eliminate the feed mechanism clearance;

(2) when the surface of the workpiece residual casting, forging process to form oxide film or other hardening layer, it is appropriate to use reverse milling.