GB/T 47248-2026Road vehicles - Safety chains for trailers up to 3.5 t (English PDF)

1 Scope

GB/T 47248-2026 is the Chinese national standard covering the safety chain on a light trailer - the last connection between trailer and towing vehicle if the coupling fails, with its strength, its attachment and the length that keeps the drawbar off the road. First edition, in force since 1 October 2026. It was issued on 31 March 2026 and takes effect on 1 October 2026, as a first edition. The document is under the responsibility of the Ministry of Industry and Information Technology. This page is published from the official record of the 2026 edition; the clause text of a standard this recent is not yet in circulation, and the figures, limits and tables it contains are those of the document itself, delivered in full with the English translation.

This Document specifies the classification, technical requirements, test methods, inspection, and marking of safety chains for trailers. This Document applies to the design, manufacture, and installation of steel safety chains for trailers with a gross mass of

2 Normative References

The provisions in following documents become the essential provisions of this Document through reference in this Document. For the dated documents, only the versions with the dates indicated are applicable to this Document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 13912 Metallic coatings - Hot dip galvanized coatings on fabricated iron and steel articles - Specifications and test methods

GB/T 20946-2007 Short link chain for lifting purposes - General conditions of acceptance

3 Terms and Definitions

For the purposes of this Document, the terms and definitions given in GB/T 20946-2007 and the following apply.

3.1 Safety chain A safety device with protective function used to ensure that a trailer shall not separate in the event of accidental uncoupling. [Source: GB/T 22550-2023, 3.6.16, modified]

3.2 Trailer gross mass The sum of the trailer's curb weight and its rated load.

3.3 Safety chain fixed point A structure that is used to secure the safety chain, which is attached to the trailer drawbar, towing vehicle towing bracket, or other components that meet strength requirements, by means of welding or bolting.

3.4 Proof force The force that is borne by the entire chain during the manufacturing and verification process of the safety chain.

3.5 Breaking force The maximum tensile force that a safety chain can withstand before it breaks during a static tensile test. [Source: GB/T 20946-2007, 3.7, modified]

4 Classification

Safety chains are classified into 4 categories. The category codes and applicable trailer gross mass shall comply with the provisions of Table 1. Table 1 -- Correspondence between safety chain category codes and trailer gross mass

6 Test Methods

6.1 Chain link and weld zone dimensions The dimensions of the safety chain links and weld zone shall be measured using vernier calipers.

6.2 Surface corrosion protection The test of the galvanized anti-corrosion coating on the surface of the safety chain shall be carried out in accordance with the method of GB/T 13912.