Some items from this specific schematic: Screw,tapping,3x16, Nut,flanged,6mm, Screw,4x20, Bulb.12v 23/8w.
With a quantity of eight pieces, the Screw,tapping,3x16 is the most used part in the TURN SIGNALS diagram.
The lowest price component in this Turn Signals parts-list fiche is the Nut,flanged,6mm.