SCREW THREAD STRUCTURE FOR PREVENTING BEING PULLED OUT AND TOOL FOR MANUFACTURING SAME

摘要

A screw thread structure for preventing being pulled out according to the present invention, with respect to a screw thread having a set pitch with a thread structure comprising, on the sides of each thread, a no-load-bearing flank which forms the forward-direction incline plane of the thread and a load-bearing flank which forms the backward-direction incline plane of the thread, has a no-load-bearing flank comprising: a first tangential part which comes into contact with the circular arc part on the tip of the counterpart thread of an object being coupled; and a second tangential part which is at a set angle from the first tangential part and which comes into contact with the circular arc part.