Parts such as the E-15 Primary Shaft: B/brg Rad N/com, Bolt,socket,6mm, Sprkt,prim,driven, B/brg Rad N/com are included in the Cb650c 1980 (a) E-15 Primary Shaft parts fiche.
The Bolt,hex., 6x16 is the cheapest item from this partsfiche.
On this parts fiche the Rubber,damper is the most specified component.