1.4mm Spring 2.Material: 45#,60#,65#,C70DA,C82DA,70#,80#,72A,72B,82B. 3. ... Of Grade 452. Material: Steel GradeGB StandardCarbon%Silicon%Manganese%Phosphorus%Sulphur %Chromium%Nickel%Cuprum%45#0.44-0.460.20-0.230 ... BuildingMachine Of Our FactoryOur Spring Products 4mm Spring Of Grade 45(45#,60#,65#,C70DA,C82DA,70#,80#,72A,72B,82B)