hot dipped spring nut: 1.Material:Carbon Steel; 2.Surface:Hot Dipped Galvanized; 3.Good price and quality; Metal stamping part/channel nutchannel ... nut(M6,M8,M10,M12,1/2",1/4",5/16",3/8"): 1.Material:carbon steel;2.Surface treament:nickel plating,,zinc ... ,M12*9.1mm,M12*11.9mm,1/4",3/8",5/16",1/2" )We hope to receive drawings or physical samples ...