The thirty-six Kaf620-p9f Mule4000 2009 Usa Fenders(p9f∼pbf) component parts are all listed in this schematic.
In this schematic the "Collar" is used most often.
A sample from the products for the Fenders(p9f∼pbf) include: Pin-snap,1.2x21.2, Washer,4.3x12.5x1, Bolt-flanged,6x16, Pin-cotter,1.6x15.