ELEMENT WITH EXTERNAL THREAD AND METHOD OF MANUFACTURE OF THE ELEMENT WITH EXTERNAL THREAD

摘要

The present invention provides a male screw part (1) comprising a head (4) and a shank portion (5) extended from the head and formed with screw threads (7), and being adapted to be screwed into a mating female screw part (40), wherein the screw threads disposed in the vicinity of a tip end of the shank portion in a direction of screwing are formed with at least one notch (12) in a heightwise direction thereof, the notch having edges intersecting with a ridgeline of the screw threads, and wherein a root diameter of the notch (X) is larger than an inner diameter of the female screw part (Y).