公开(公告)号：US20210254652A1

公开(公告)日：2021-08-19

申请号：US17251595

申请日：2019-06-12

Applicant: TOPURA CO., LTD.

Inventor： Naoki HORIUCHI ,  Keisuke HIBINO

IPC: F16B33/02 ,  F16B35/04

Abstract: An external thread member capable of preventing oblique entry or insertion by a short screw tip shape is provided including, in its shank portion (20), a normal thread area (22), a guide thread area (24) provided at a tip side of the shank portion with respect to the normal thread area (22) and in which a guide screw thread (23) is formed, and a rising area (26) in which a transition screw thread (25) gradually rising from the guide screw thread (23) to the complete screw thread (21) is formed. A tapered guide portion (30) is provided at a tip end side of the normal thread area (22) and includes at least the guide thread area (24). The guide screw thread (23) is formed on an outer periphery of the tapered guide portion (30) which has a maximum diameter equal to or smaller than an inner diameter of an internal thread.