Carbon Steel Coil Spring 1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5, ... 0.1-3.0mm 3) Width: 3-80mm Carbon Steel Coil Spring1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5, ... , electrical machine ,start-up machine,etc.),constant force spring for door ,windows ,electric fans ,machines of lift ... for various kinds of carbon and stainless steel products and supplies high elastic and heat treatment stainless steel ...