Road vehicles - 50 semi-trailer fifth wheel coupling pin - Basic and mounting/interchangeability dimensions (ISO 337:1981, IDT)
This Malaysian Standard specifies the dimensions of the 50 [diameter at 50.8 m m (2 in)] 3 fifth wheel coupling pin which is used for coupling semi-trailers to prime movers, taking into account the limitations of weight generally laid down by official requirements.
NOTE - If, for extra heavy-duty vehicles, this coupling pin is not sufficient, an 90 I@ 89 mm (3.5 in)1 fifth wheel coupling pin according to IS0 4086 shall be used. In addition, this Malaysian Standard specifies the dimensional characteristics necessary for mounting and interchangeability.
