... :60Si2Mn, SUP9 ,50CrVA 2.Type:guide arm,parabolic,variable section,suspension 3.ISO 9001:2008 QS-9000 Shock Absorber Leaf SpringsProduct ... ):120Weight(KG):109Equipment Capacity:160TA. specifications of materials (the leaf springs with more than 13mm thickness are made of 50CrV,55SiMnVB ... our customers the shortest lead time in the industry. Trailer Suspension Springs