The invention relates to fastening device with a fastener, a first washer, and a second washer. The fastener has a head with a head contact surface and a pin which extends outwards from the head along a longitudinal axis, and the pin has a fastening end with a contact surface opposite the head contact surface. The first washer has an opening, which is suitably large enough to allow the pin to pass through the opening, and a wedge-shaped sub-portion. The second washer has an opening which is suitably large enough to allow the pin to pass through the opening and to allow a rotation of the second washer relative to the fastener about the longitudinal axis of the pin. The second washer contacts the wedge-shaped sub-portion and moves along the surface of the wedge-shaped sub-portion when the second washer and the fastener rotate relative to each other about the longitudinal axis of the pin.