拉刀是传统的半精加工和精加工内孔的刀具,加工精度为IT9～IT7级,表面粗糙度R_o3.2～0.8。它不但适用于加工直径10～85mm的普通孔。近几年来由于拉孔工艺的改进,其最大和最小加工的孔径已分别达到了200mm和5mm,深径比可达15,精度可提高到IT6级,表面粗糙度可达R_o0.4～0.2。但用拉刀拉削内孔时,由于拉刀本身或使用不当,常会产生拉削表面 Broach is a traditional semi-finishing and finishing the hole tool, processing accuracy of IT9 ~ IT7 level, surface roughness R_o3.2 ~ 0.8. It is not only suitable for the processing of ordinary holes 10 ~ 85mm in diameter. In recent years due to the improvement of the hole punching process, the maximum and minimum processing diameters have reached 200mm and 5mm, respectively. The aspect ratio can reach 15, the accuracy can be improved to IT6 level, and the surface roughness can reach R_o0.4 ~ 0.2. However, broaching with a broach bore, due to broach itself or improper use, often produce broaching surface