On this parts fiche the Bolt(6x20) is the most specified component.
This schematic depicts all components used in the Vl800 Volusia 2001 (k1) Usa (e03) Rear Swinging Arm (model K3/k4/k5) partslist.
The Rear Swinging Arm (model K3/k4/k5) is made up of components including this Swingingarm Se which is the most expensive.