FALLING-OFF PREVENTION DEVICE AND LOOSENING PREVENTION NUT

摘要

An object of the present invention is to provide a fall-off preventing element and a loosening preventing nut, which, by a wire of a coil spring, with a free lower end, being fitted onto a thread groove of a bolt, can prevent fall-off of a nut or loosening of a nut. [Solution Means] The present invention provides a fall-off preventing element (1) that is screwed onto a bolt and includes: a coil spring portion (3); and a cylindrical main body (2), affixing an upper end of the coil spring portion and having an opening (7) formed therein in which a lower end of the coil spring portion is latched; and the coil spring portion is made smaller in its inner diameter than the outer diameter of a leg portion of the bolt, the lower end of the coil spring portion is latched in a diameter-expanded state to the cylindrical main body, and the lower end of the coil spring portion is enabled to move in a diameter-expanding direction.