Parts such as the Rear Hub: Nut,6mm, Joint-chain,ek428-g, Bolt-upset, Panel-assy-brake,rr are included in the Ke100-b15 1996 United Kingdom Rear Hub parts fiche.
On this parts fiche the Nut,10mm is the most specified component.
The component with the lowest price in the REAR HUB schematic is the Nut,10mm.