AS 4177.3-1994

Specifies classification, design, interchangeability dimensions with tolerances, finish, marking requirements for coupling body for 50 mm towballs, which are used for the towing of caravans, very light and light trailers of up to 3.5 t in tension and compression, transverse thrust and pull-out forces. A static strength test and a dynamic test are also described in the appendices.