In this schematic the "Bolt, Rear (8x30)" is used most often.
The Washer,8.5x16x is the cheapest item from this partsfiche.
Parts such as the Steering Stem (gsx500ese/esf): Nut,m8x1.25x12, Bearing, Lock Washer, Bolt are included in the Gsx500es 1984 (e) General Export (e01) Steering Stem (gsx500ese/esf) parts fiche.