The Screw Flat 6x16 is the cheapest item from this partsfiche.
This schematic depicts all components used in the Cb250 Two Fifty 1992 (n) Spain Crankshaft/piston partslist.
A sample from the products for the Crankshaft/piston include: Ring Set,piston,0, Clip,piston Pin, Pl,oil Through, O Ring 6x3.