0.15mm Spring Steel Strip 1.Material: 65, 70, 75, 85, 65Mn, etc 2.Thickness:0.15mm-2.0mm 3.Width:30mm-355mm Specification of Spring Steel Strip for Roller Shutter Doors :1.Material: 65, 70, 75, 85, 65Mn, 55SiMnV, 60Si2MnA, 60Si2CrA, etc.2.Thickness:0.15mm-2.0mm3.Width:30mm-355mm4.Hardness:≥100HV5.Surface Treatment: grey, blue, bright, bright & grey, bright & blue6.Features: The chemical ...