Standard:SAE Chemical Composition(%): C 0.85-1.20 Mn 0.60-1.20 Si 0.40-1.20 S <0.05 P <0.05 Hardness:GP Steel Grit HRC 42-50;GL Steel Grit HRC 56-60:GH Steel Grit HRC 63-66 Hardness Deviation:Max Deviation ?.0 HRC Metallographical structure:Even Tempered Martensite Min Density(Can be determined By alcoholic displacement):7.4g/cm3