Describes the requirements of high tensile steel chain grade 40. Covers types of chain, quality of material, heat treatment, quality marking, dimensions of links, tolerances on pitched or calibrated chain, workmanship, testing machine, proof testing, inserted links, correctness of the pitch of pitched chain, selection of samples for mechanical tests, breaking test, ultimate breaking load, energy absorption factor, up-ending test, inspection marking, identification marking, additional tests before rejection, condition, certificate of test and examination, testing facilities and inspection.