Parts such as the Seat: Rubber,seat Sett., Bolt,hex 6x12, Nut,hex.,8mm, Catch Comp,seat are included in the Cb250k0 Sweden Seat parts fiche.
On this parts fiche the Washer,spring,6mm is the most specified component.
The Bolt,hex 6x12 is the cheapest item from this partsfiche.