... -16mm 2.Material: 60si2MnA spring steel 3.Style: coil Detailed Product Description1) Air brake main spring for commercial brake spring and trucks2) Material: 60Si2MnA ... nameBrake springsItem number153,151,Xiaojinlong,etcMaterial availablecarbon steel wire, stainless steel wire, spring steel, brass, aluminum, copper, alloy, etcSurface treatmentpolishing, anodizing, zinc plating, nickel ...