Aramid fiber-reinforced composites (AFRP) are widely used in aerospace, and their hole making process is very likely to lead to problems such as burr, delamination, and resin debonding. In order to reduce the hole making defects and overcome the shortcomings of traditional tools with low shear force, a drilling and milling composite tool with a stepped structure is designed, which can effectively reduce the cutting force. By analyzing the shear effect of the tool on the aramid fiber material during the cutting process, the side edge structure of the tool with different shear angles (side edge sharp angles \(\varphi_1=155^\circ\) , \(\varphi_2=135^\circ\) , \(\varphi_3=115^\circ\) ) was selected and tested in comparison with the twist drill. The results show that when the drilling and milling composite tool side edge sharp angle is 135°, the hole and hole wall of AFRP are processed with the best quality, the tool side edge is complete and more polished, and the Maximum thrust force is 52.6%–73.3% lower than that of twist drill. At a feed rate of 10 mm/min, the Maximum thrust force was 50.4% lower for the 135° side edge sharp angle than for the 115° side edge sharp angle tool and 63.4% lower than for the 155° side edge sharp angle tool. It was found that the drilling and milling tools transformed the tensile fracture of fibers during twist drilling into shear fracture of fibers, and the smaller the shear angle, the easier the fibers were to be shear fractured. This provides a new solution for high-quality hole making in AFRP, as well as tool design.
