... 3.JISG4801/GB/T 1222 4.Surface:Smooth,Double Groove 60Si2Mn spring flat steel priceSpecification1) Grade: 60Si2Mn,SUP7,G92600, ... 2-8m, or as your requirements4) Surface: Smooth Plain, Double Grooved5) Heat Treatment: Quenching and Tempering6) Quenching Temperature: 870 ... and railway carriage, cylinder relief valve spring, check valve spring and the heatproof spring in the non-corrosive medias under the ...