The Washer,plain,5mm is the lowest priced item on this Radiator schematic.
Parts such as the Radiator: Collar,rad Mt, Clip B10,tube, Joint,tube, Rubber,rad.mount are included in the Vt1100c3 Shadow Aero 1998 (w) Canada / Cmf Radiator parts fiche.
With four applications this Clamp,hose,24-32 is the most specified part.