The purpose of this standard is to establish the requirements required for a series of high quality chains intended for special uses, calibrated, made of high tensile strength steel, electrically welded (round links) manufactured especially for use in mining equipment, such as: a) Flexible and rigid chain conveyors, belt conveyors with traction chain, distribution conveyors. b) Carbon brushes, miners and electric loaders. c) Ferris wheels. d) Other similar mining machines. This standard is applicable to chains with dimensions between 14 and 30 mm. Three qualities are specified (B, C and D) defined by the mechanical characteristics of the chain. However, the values referring to quality D in tables 3, 4 and 8 are provisional. The chains to which this standard applies are not intended for use in lifting devices such as cranes or slings.