... .JISG4801/GB/T 1222 4.Surface:Smooth,Double Groove 60Si2Mn spring flat steel priceSpecification1) Grade: 60Si2Mn,SUP7,G92600,61SiCr7,60Si7 ... bears high load on railway vehicle, automobiles and tractor or spiral spring whose diameter is not more than 30mm, such as ... car and railway carriage, cylinder relief valve spring, check valve spring and the heatproof spring in the non-corrosive medias under the ...