Abstract: Based on chip-splitting principle and tool’s movement feature, a new specialized tool for helical milling with distributed multi-point front cutting edge is designed. The description of each cutting edge’s movement track and simulation of chip shape are used to analyze the chip-splitting result, the different function of front and peripheral cutting edges and the specialized tool’s service life. The helical milling contrast and life experiment of aluminum alloy, titanium alloy and carbon fiber reinforce plastic (CFRP) are used to testify the chip-splitting result, the hole quality and the service life of the specialized tool. Results show that the specialized tool can machine titanium holes without burr and CFRP holes without delimitation under dry cut condition during domestic aircraft assembly and the specialized tool’s service life prolongs. The problems of poor hole quality and short tool service life when helical milling of aeronautical hard-machining materials such as CFRP and titanium alloy with end mill under dry cut condition is solved and the requirement of the engineering application is met.

Key words: chip-splitting;helical milling;multi-point front cutting edge;specialized tool;end mill;dry cut