粗车螺纹时,为了改善切削条件,根据工件材料不同,螺纹车刀通常都磨出一定的径向正前角,如图 1所示。有径向前角的螺纹车刀,因刀刃并不通过工件的轴心线,使螺纹车刀沿其前刀面上的刀尖角小于螺纹牙形角。因此,其刀尖角必须修正。本刊1981年第2期现场资料“螺纹车刀牙形角的修正值”一 In the case of roughing thread, in order to improve the cutting conditions, the thread turning tool usually grinds a certain radial positive rake angle, as shown in Fig. 1, depending on the workpiece material. Radial rake angle thread turning tool, because the blade does not pass the axis of the workpiece, so that the thread along the cutting edge of the knife edge angle less than the thread angle. Therefore, the nib angle must be corrected. This issue No. 2 of 1981 on-site information “thread lathe tooth angle correction value” one