... coil Detailed Product Description1) Air brake main spring for commercial brake spring and trucks2) Material: 60Si2MnA,55CrSi ... The domestic market share 70% in brake spring. . Item nameBrake springsItem number153,151,Xiaojinlong ... treatmentpolishing, anodizing, zinc plating, nickel plating, etcTypeCompression spring,Auto spring,others.Applicationauto, toy, electronics, medical device, motorcycles, ...