碳 C ：0.27～0.35(答应偏差：±0.01)

硅 Si：≤0.25

锰 Mn：0.50～0.80(答应偏差：±0.02)

硫 S ：≤0.035

磷 P ：≤0.035

铬 Cr：答应残余含量≤0.020

镍 Ni：答应残余含量≤0.020

铜 Cu：答应残余含量≤0.020

【冷镦钢】：SWRCH6R SWRCH8R SWRCH10R SWRCH12R SWRCH15R SWRCH17R SWRCH6A SWRCH8A SWRCH12A SWRCH10A SWRCH15A SWRCH16A SWRCH18A SWRCH19A SWRCH20A SWRCH22A SWRCH25A SWRCH10K SWRCH12K SWRCH15K SWRCH16K SWRCH17K SWRCH18K SWRCH20K SWRCH22K SWRCH24K SWRCH25K SWRCH27K SWRCH30K SWRCH33K SWRCH35K SWRCH38K SWRCH40K SWRCH41K SWRCH43K