Combined tool with cooling function for machining stepped holes

The invention belongs to metal cutting tools, and particularly relates to a combined tool for machining stepped holes. The combined tool comprises a milling cutter (1) with an inner cooling hole, an adjusting shaft sleeve (2) and a twist drill (3) with an inner cooling hole. The milling cutter (1) with the inner cooling hole is in threaded fit with the twist drill (3) with the inner cooling hole, the stepped holes of different types and sizes are machined, the investment of equipment and tools for machining the stepped holes is reduced, machining procedures and auxiliary working hours are reduced, the inner cooling holes are formed, cutting fluid flows in the tool, and the cooling effect of the tool is improved. 本发明属于金属切削刀具，特别涉及一种阶梯孔加工组合刀具。包括带内冷却孔的铣刀（1）、调整轴套（2）、带内冷却孔的麻花钻（3）。带内冷却孔的铣刀（1）与带内冷却孔的麻花钻（3）螺纹配合，加工不同类型和尺寸的阶梯孔，减少阶梯孔加工的设备、刀具投资，减少加工工序和辅助工时，均有内冷却孔，切削液在刀具内部流动，提高刀具的冷却效果。