本国际标准规定了车辆所需的50 mm牵引杆孔的特性 挂车上联轴器部件的互换性以及牵引车之间的互换性 以及装有这些部件的拖车。 本国际标准适用于为商用车辆和挂车设计的机械连接， 其最大总质量在3.5t以上。

This International Standard specifies the characteristics of 50 mm drawbar eyes, necessary for the interchangeability of the coupling components on trailers and permitting interchangeability between towing vehicles and trailers equipped with these components. This International Standard is applicable to mechanical connections designed for commercial vehicles and trailers, the maximum total mass of which is above 3,5 t.