The lowest price component in this Rear Hubs/brakes parts-list fiche is the Washer-spring,18mm.
In this schematic the "Bolt-upset-ws,10x16" is used most often.
This schematic depicts all components used in the Kaf620-mbf Mule4010 2011 Usa / 4x4 Rear Hubs/brakes partslist.