On this parts fiche the Bolt,flange,12x40 is the most specified component.
Parts such as the Step: Pin Cotter 3.0mm, Pedal,gear Change, Bar, L. Step, Bolt,flange,12x40 are included in the Trx125 Fourtrax 125 1987 (h) Usa Step parts fiche.
The eighteen Trx125 Fourtrax 125 1987 (h) Usa Step component parts are all listed in this schematic.