Secondly there is error between the thread roll angles of thread rollingdie and drill rod.
滚丝轮螺纹和钻杆螺纹的螺旋角有误差。
2
The some experienced data have been given, so the cold rollingdie design is more simple and practical.
其中给出的部分经验数据使冷辗模具设计简单实用。
3
The arrangement of the wedge rollingdie was described, and the design and calculating procedure for the wedging zone, spreading zone and finishing zone were stated.