This schematic depicts all components used in the Tt250rl 1999 4px5 Australia 294px-700e1 Rear Wheel partslist.
On this parts fiche the Bolt, Hexagon Socket Head(38v) is the most specified component.
A sample from the products for the Rear Wheel include: Rim (2.15-18), Nut, Castle(3sh), Oil Seal(39x), Tire (4.60-18)(4gy).