... spring steel plate. Steel grade:SUP11A 60Si2Mn,65Si7,SUP9,SUP9A,SAE5160H,50CrVA,SAE615. Spring steel plates and Spring round bar1),Steel ... grade:60Si2Mn,65Si7,SUP9,SUP9A,SUP11A SAE5160H,50CrVA,SAE6150H.2),65Mn:Specroundφ12φ50 flat45×5120×12 ...