A washer (14) and a threaded assembly (22) between a screw (30) and a workpiece (42) are provided. The washer (14) is offset up to an angle (α) with respect to a flat initial state, such that the washer has an insert thickness (De) that is substantially greater than the initial thickness (Da) thereof. The washer (14) is made of a malleable material. The length (Lg) of an unthreaded shank section (40) of the screw (30) is smaller than the sum of the thickness (Dw) of the workpiece (42) and the insert thickness (De) of the washer (14), and essentially not smaller than the sum of the thickness (Dw) of the workpiece (14) and the insert thickness (Da) of the washer (14). When the last thread of the screw (30) leaves the workpiece (42) on being screwed in, the force previously exerted on the washer (14) by the feed of the screw is zero. The washer (14) has been plastically deformed thereby, such that the washer retains the flattened state thereof and bridges the space between the workpiece (42) and the screw head (34) free from play. The workpiece (42) and the washer (14) thereby remain firmly clamped between the head (34) and the thread (36) of the screw (30), and the prevention of inverse rotation is ensured.