The Nut,flange, 6mm is the lowest priced item on this F-7 Front Wheel - Panel schematic.
Parts such as the F-7 Front Wheel - Panel: Nut,slotted 12mm, Indicator,fr.brk., Collar,fr Wheel, Joint, Brake Arm are included in the C90k3 General Export (kph) F-7 Front Wheel - Panel parts fiche.
In this schematic the "Spoke A,12x159.5" is used most often.