Trailer and truck leaf spring bushing Material:60Si2Mn, SUP9 ,50CrVA Type:guide arm,parabolic,variable section ISO 9001 Trailer and truckl leaf spring bushing1.thinkness:6-40mm2.material:60si2Mn,SUP9,50crVA51crv43.OEM:serviceODM:service offord4.ISO:9001-2008QS-90005.Type:guide arm variable section suspension