| 摘要 |
PROBLEM TO BE SOLVED: To improve workability by easily screwing a loosening prevention nut into a bolt, and to surely perform loosening prevention by preventing damage and seizure of a thread.SOLUTION: In a loosening prevention nut in which a flat plat-like elastic washer 2 is caulking-fixed to an upper end part, on the inner peripheral surface of the elastic washer 2, formed are first and second projected engagement pieces 21, 22 that project inwardly in a radial direction and of which a projection inner peripheral surface is formed into an arc shape so as to have a substantially same diameter as the inner diameter of a screw hole 1a, and first and second cutout recess parts 23, 24 of which an inner surface is formed into an arc shape so as to have a larger diameter than a root diameter of the screw hole 1a, which are formed alternately. Also, curvature guide parts 21a, 22a are formed at the respective projection peripheral edge parts of the first and second projected engagement pieces 21, 22 so as to be curved upward.SELECTED DRAWING: Figure 3 |
