The Washer Plain 6mm is the cheapest item from this partsfiche.
A sample from the products for the Front Fender include: Nut,hex.,6mm, Fende,fr*nh-193p*, Bolt Flange 6x12, Bolt,fr.fender Fi.
This Front Fender diagram displays the required parts for the Xl600v Transalp 1988 (j) England Front Fender.