Abstract: A fastening assembly, comprising a nut and a washer, where the nut is provided with a threaded hole and a nut head, the nut head forms plural consecutive ramps. The threaded hole forms a barrier surface. The washer has a through hole and an diameter-enlarged hole, and the through hole and the diameter-enlarged hole form a shoulder at their junction. The washer is provided with consecutive ramps with the same number as that of the continuous ramps of the nut. The barrier surface of the nut confines the shoulder of the washer that the washer is not allowed to separate from the nut. The nut and washer can be relatively free to rotate, so that the two will not result in deadlocked state prior to their actual usage, to ensure that the anti-theft and locking features achieve the goal of preventing the illegal theft and destruction.