Patent ID: 9689417
Date: 2017-06-27
CPC Classifications: F16B

Claim:
1. A fastener arrangement that includes: a threaded fastener having a head including a free end, and a flange with an undersurface axially opposite of the free end and having an undersurface periphery, and a washer disposed adjacent to the undersurface of the threaded fastener, and having a domed central portion that is outwardly convex facing the undersurface and that has a planar fastener engagement surface, a center opening in the central portion, and a curled periphery having a free edge, and wherein the washer comprises a body of revolution around an axis of the center opening, wherein the threaded fastener and the washer are configured such that threaded tightening of the head against an underlying support structure collapses the central portion and curls the periphery of the washer around the periphery of the head with a radial space therebetween, and so that the free edge of the curled periphery of the washer is axially spaced between the fastener head flange and the fastener head free end to indicate complete tightening of the fastener arrangement to an object.