Parts such as the Rear Fender: Nut 6mm, Washer, Washer, Mud Guard,rear Fender,front are included in the Gsxr1100 1986 (g) Usa (e03) Rear Fender parts fiche.
On this parts fiche the Screw is the most specified component.
The component with the lowest price in the REAR FENDER schematic is the Bolt.