Patent attributes
The present invention is configured by a wood screw main body, and a truncated cone-shaped washer that is rotatable in relation to a head of the wood screw main body such that a top surface of the head and a top surface of the truncated cone-shaped washer are substantially on the same plane, and attached so as not to detach from the head. When a retainer element is secured by the wood screw to a wood material to be supported, frictional heat can be prevented from occurring in the retainer element, and the retainer element can be secured by only the fastening force of the wood screw. The retainer element can be efficiently prevented from breaking, and attached such that the head of the wood screw and the surface of the retainer element are on the same plane.