The groove wall 61 on the side with shoulder rib is connected with the groove bottom deepest part 71 in that condition by the curved surface part 75 on the side with shoulder rib.
与轴肩挡边处于一边的沟墙61被连接于沟底深中心71处,这样一来,弯面75就与轴肩挡边在一边了。
2
After processing LET thread, stress groove and double shoulder connection for the NC35 thread of Drill Collar in 43/4 inch, torsion tests were done.