This Japanese Industrial Standard specifies the ductile iron fittings used for carrying water and the like, under pressure or non-pressure, through fittings buried underground or laid on the ground. The fittings are manufactured by dissolving the appropriate raw materials to ductile iron, carrying out the optimum treatment for spheroidizing of graphite as cast, pouring into the mould and casting. Further, if necessary, the fittings shall be heat-treated for annealing and the like.

JIS G 5527:2014

ISO 2531:1998 - Equivalent