Clamping processing center mills end mills they use a spring clip package folder ways, when used in a cantilever state. May sometimes occur in the milling process, the milling cutter projecting from the toolholder gradually even completely Drop resulting workpiece scrapped phenomenon, generally because the toolholder shank between the outer diameter of the inner hole and endmills the presence of the oil film, resulting in insufficient clamping force. Factory mills are usually coated with anti-rust oil, use a non-water-soluble cutting oil, cutting toolholder bore will be attached to a layer of mist film toolholder shank and toolholder on film there it is hard to firmly clamping shank, it is easy to loose drop in processing neutral cutter. Should first stand before clamping end mills, milling shank and toolholder within the hole cleaned with cleaning fluid, dry and then clamping. Diameter larger mills, even if the knife handle and toolholder very clean or out knife accidents may occur, should be used with flattened notched the knife handle and the side locking. Another problem that may arise is clamping legislation cutter processing neutral cutter in toolholder port at the break, the reason toolholder long time use toolholder port Ministry worn due to the tapered, the should be replaced with a new knife folder.