The Washer-spring,18mm is the lowest priced item on this Rear Hubs/brakes schematic.
Some items from this specific schematic: Spring,brake,lh, Washer-spring,18mm, Nut,18mm, Washer,spring,6mm.
The Bolt-upset-ws,10x16 is the most widely applied product in the KAF620-C3 MULE 1997 USA, CANADA REAR HUBS/BRAKES ( eight times ).