Abstract: The research indicates it is impossible that cutting speed is improved decuple in accordance with present cutting theory. A new theory on super high-speed milling is put for-ward, in milling machining, the temperature of cutting zone increases as a result of distortion and friction, strength and hardness descend prominently. On the other hand, the temperature of cutting tool is kept under 300℃ and the hardness is invariable, so the ratio of cutting tool and workpiece hardness increases and super high-speed (vc=8500m/min) milling is achieved. The theory has already been proved reasonable.

Key words: Super high-speed cutting, Super high-speed milling