The most reasonably priced component used on the Pa50ii Hobbit 1981 (b) Usa / 30 Mph Crankcase / Inlet Pipe is the Bolt,hex 6x25.
This CRANKCASE / INLET PIPE assembly utilises five Screw Cross 6x45(s) - the highest specified component.
Some items from this specific schematic: Screw Cross 6x80, Bolt,stud,2.6x18, Bolt,hex.,6x40, Bolt,hex 6x25.