1.4mm Spring 2.Material: 45#,60#,65#,C70DA,C82DA,70#,80#,72A,72B,82B. 3.Spring for mattres,shock absorbers 4. ... Best price 1. Product Name: 4mm Spring Of Grade 452. Material: Steel GradeGB StandardCarbon%Silicon%Manganese%Phosphorus%Sulphur %Chromium%Nickel%Cuprum%45 ... steel wires, low carbon steel wires.Spring steel wires, mattress spring steel wires.6. Our other material: 60#,65#,C70DA,C82DA,70#, ...