This M/c Sub Assy,rr is the most expensive of the items that make up this Rear Brake Mastercylinder (cb600f/f3) assembly.
On this parts fiche the Washer,oil Bolt is the most specified component.
The component with the lowest price in the REAR BRAKE MASTERCYLINDER (CB600F/F3) schematic is the Screw-washer,4x12.