... ) Hardness: HRC50-633) Chemical elements: C: 0.52-0.65, Si: 0.15-0.37, Mn: 0.6-1.2, P ... ) Hardness: HRC58-653) Chemical elements: C: 0.7-0.9, Si: 0.45-0.75, Mn: 0.7-1.25, P ... ) Hardness: HRC60-653) Chemical elements: C: 0.72-0.82, Si: 0.17-0.37, Mn: 0.7-0.8, P ...