... steel flat bar 1. Spring steel bar 2.Material: 65Mn, 60Si2Mn, SUP9, SUP7, 50CrVA 3. Size: 6*40~20*150 Double grooved Spring ... steel flat bar We're a big steel mill, and can ... produce high quality spring steel flat bar by our own factory.Double grooved Spring steel flat bar 1. Material: 65Mn, 60Si2Mn, SUP9, SUP7 ...