钻杆螺纹除了起连接作用外，主要是传递扭矩。但频繁的拧、卸却是钻杆螺纹磨损的重要原因。欲延长钻杆螺纹的寿命，除了提高钻杆接头的材质、加工精度及热处理工艺之外，还必须有合理的螺纹公差值和公差范围。这些数值的大小决定着钻杆螺纹拧卸回 In addition to the drill pipe thread connection role, the main transmission torque. But frequent screwing, unloading is an important reason for wear of drill pipe thread. To extend the life of the drill pipe thread, in addition to improving the quality of the drill pipe joints, machining accuracy and heat treatment process, there must also be reasonable thread tolerance values ​​and tolerances. These values ​​determine the size of the drill pipe thread unscrewed