Carbon Steel Coil Spring 1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5 ... .1-3.0mm 3) Width: 3-80mm Carbon Steel Coil Spring1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5, ... manufacturer specialized in producing all classes of springs for Industrial machine,(ie. garden hose reels, balancer, ... , electrical machine ,start-up machine,etc.),constant force spring for door ,windows ,electric fans ,machines of lift and ...