Description::with special processing technology, the knife inside was hollowed and the waste is blocked in the blade cavities and fell down into the inside of tooling automatically, then taken out via the waste-discharging holes at the side of tooling. this kind of waste-discharging is processed with no noise, but the waste shape is requested to be regular shape, such as round hole or square hole. it is most suitable for the production with 3-10mm of diameter of round holes.