1、The internal cooling through hole and the central through hole design are conducive to water cooling 2、Anti-vibration and more anti-bending, which helps for reducing the use of long knives 3、Advanced vacuum quenching furnace can realize carbon and oxygen co-permeation to increase the hardness of the tool shaft and enhance the lifespan 4、Hex nut is convenient for clamping, loading and unloading more convenient, possess high rigidity, strong clamping force 5、The UM type ER extension rod is tightly fitted with fine teeth. The size of the ER chuck used for mounting is different, and the size of the nut is also different 6、Can reduce the use of lengthened tools, which will reduce costs and improve efficiency 7、Outer diameter of the extension rod and other parts are accurately ground to eliminate the imbalance and increase the stability during cutting