1.型钻杆接头苏联型钻杆接头有两种型号:-50和-42型,其外形如图1所示.用于地质勘探钢质钻杆连接.当钻孔直径为59(76)mm时,钻深为2000m(与轻合金钻杆组成复合钻杆柱).内螺纹(端部)和外螺纹(尾部)均有导向颈.对于锥形螺纹连接,导向颈有对中和保护螺纹的作用.对于圆柱形螺纹连接,导向颈可以增加连接处的刚度,预防钻杆柱折断.为增加接头的横截面积,接头外径有所增大,内径有所缩小.接头 1. Drill Pipe Fittings There are two types of Soviet Drill Pipe Fittings-Type -50 and -42, which are shown in Figure 1. They are used for geological exploration of steel drill pipe connections. When drilling a hole diameter of 59 (76) mm, drilling depth is 2000m (composite drill string with light alloy drill pipe) Both the internal thread (end) and external thread (tail) have a guide neck For centering and tapered thread connection, the guide neck is centered and protected For cylindrical threaded connection, the guide neck can increase the rigidity of the joint to prevent the drill string from breaking off. In order to increase the cross-sectional area of ​​the joint, the outer diameter of the joint is increased and the inner diameter is reduced.