DIES FOR MANUFACTURING ANTI-VIBRATION BOLT

摘要

PURPOSE: A dies for manufacturing an anti-vibration bolt is adapted for rolling thread. The present dies is provided to solve drawbacks in a conventional dies that the cost for manufacturing the anti-vibration bolt is high and the use of the bolt is not convenient, since a washer for preventing the vibrational loosening has to be made separately as a part of a bolt and nut not to be loosed. CONSTITUTION: In a dies for manufacturing an anti-vibration bolt, an angle of threads having a constant pitch and root diameter is formed on an outer diameter portion of the dies. In addition, indents formed to be directed to a center portion and to be inclined inwardly from the opposite sides based on the center portion of the outer diameter portion are formed at an outer diameter portion of the angle of thread.