1.1 This standard Jays down the strength require-ments to be met by mechanical coupling devices between trailers and towing vehicles. These devices may be of the following types:
a) One-piece ball coupling, and
b) Ball coupling comprising of a number of parts which can be dismantled.
NOTE — The term 'ball coupling' is used to desig-nate a coupling device of which a 'coupling ball' forms a part.
1.2 This standard is applicable to towing brackets and coupling balls fitted to towing vehicles intended for towing of the trailers of which the maximum total weight does not exceed 3-5 tonnes. In the case, where exceptionally, the manufacturer of the towing vehicles authorizes the maximum permis-sible towed weight to be exceeded, the corres-ponding towing devices are not considered in this standard.
IS 12605-1989 history
1989IS 12605-1989 Test method for strength of trailer traction brackets and connecting balls