Two design program methods on inside tapered thread (left- ha nd)of the normal drill -pipe joint . They are cutting thread (G32) and fixed cyc le of threading(G82). They completed cutting thread machine, they are new machi ne way and track.

• 介绍正规式钻杆接头 7 5 /8"左旋内锥螺纹的两种程序编制方法,即切削螺纹(G32)和螺纹切削固定循环 (G82 )的程序编制,完成了对 7 5 /8"左旋内螺纹的一次性完整挑扣加工,探索出左旋内锥螺纹加工的一条新途径和新方法。