The Nut,hex.,8mm is the lowest priced item on this Cam Chain/tensioner schematic.
Parts such as the Cam Chain/tensioner: Arm,tensioner, Pin, Roller, Washer, Sealing, Springa,tensioner are included in the Z50j Monkey 1979 (z) General Export (mph) Cam Chain/tensioner parts fiche.
The Honda CAM CHAIN/TENSIONER has twenty-three products enlisted in the schematic.