圆孔拉刀经多次刃磨后 ,拉出的孔内表面质量往往很差 ,呈鱼鳞状 ,且拉刀易发热、易断。现场实践中发现 ,在这些拉刀的校准齿容屑槽中 ,往往缠有环状铁屑 ,用钢丝刷难以去除 ,这就是产生上述表面质量缺陷的原因 ,铁屑使拉刀与孔的切削不再是均匀而全面的 ,而成为一种不规则的切 Round hole broach after multiple sharpening, the quality of the surface of the hole pulled out often poor, was scaly, and broaches easy to heat, easily broken. Field practice found that in these broach calibration tooth flutes, often wrapped around the ring of iron filings, difficult to remove with a wire brush, which is the reason for the above-mentioned surface quality defects, iron filings make broaching and hole cutting No longer uniform and comprehensive, but an irregular cut