This standard specifies the dimensions of the 50 [φ50.8 mm] fifth wheel coupling pin which is used for coupling semi-trailers to prime moverstaking into account the limitations of weight generally laid down by official requirements.
Note: If for extra heavy-duty vehiclesthis coupling pin is not sufficientan 90 [φ 89mm] fifth wheel coupling pin according to GB/T 4607 shall be used.
In addition, this standard specifies the dimensional characteristics necessary for mounting and interchangeability.
2 Normative References
The following normative document contains provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies.
