discount Malleable Iron Npsl Threaded Lock Nut Our History Hebei Jianzhi Casting Group Co., Ltd. is one of the largest manufactures of Malleable Iron Pipe Fittings in China, and has the history of more forty years. and has the history of more than twenty years. Once it was named as Tangshan Malleable Iron Plumbing Industry Co.,Ltd. and then Tangshan Jianzhi Malleable Iron Co.,Ltd. Our Factory...