North First St. and BBT both sides when positioning the spindle taper portion locking handle, eliminating the centrifugal force generated by high-speed rotation due to the expansion and the expansion of the Z-direction due to thermal expansion generated sinking, tool life and improve the processing efficiency while improving fine surface finish of the machined surface. Features: Excellent maneuverability. Apex slender, easy to operate. Simple knife. Cooling can be achieved. A strong clamping force. Low cold treatment. Vertebral contact precision. High rigidity.