Carbon Steel Coil Spring 1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5, SUS301,304 2) ... : 0.1-3.0mm 3) Width: 3-80mm Carbon Steel Coil Spring1) Material: 62Si2MnA, 65Mn, SK3,SK4, SK5, SUS301,3042) Thickness ... , diesel oil , electrical machine ,start-up machine,etc.),constant force spring for door ,windows ,electric fans ,machines of lift and down ...