This International Standard specifies the dimensional characteristics necessary for the mounting and interchangeability of the fifth wheel on the frame (subframe or mounting plate) of towing vehicles for semi-trailers. It is applicable to fifth wheels intended for hitching on semi-trailers equipped with a
- 50 kingpin as defined in ISO 337, or
- 90 kingpin as defined in ISO 4086.
Dimensions not specified are left to the discretion of the component manufacturer.
NOTE Those test conditions and strength requirements to be met by 50 and 90 fifth wheel couplings are specified in ISO 8717.