In this schematic the "Washer,plain, 6mm" is used most often.
A sample from the products for the F-18 Rear Fender include: Grommet,wire Cord, Washer,plain, 6mm, Rubber,rr.fender, Collar,fr.fender.
This Fender,rr.*r-23* is the most expensive of the items that make up this F-18 Rear Fender assembly.