Ming Yuan Metal Products (Shanghai) Co., Ltd Hotline 57,888,255; Fax: 57888225; Mobile: 15221352988; (1) characteristic JISG 4051-79 (94) standard steel, High quality carbon steel. The steel is manufactured by the furnace, open hearth, or oxygen converter steelmaking method static steel, wear resistance and toughness of a high, uniform microstructure of the steel, and excellent processability. The S30C strength and hardenability steel than on the 30th secondary welding, cold deformation, the plastic medium, good machinability, usually in the normalizing condition for the manufacture of bolts, nuts, leverage and work under high stress Small parts. (2) Availability state of hardness 152 ~ 212HBS. (3) chemical composition (wt%) C 0.27 ~ 0.33, Si 0.15 ~ 0.35, Mn 0.60 ~ 0.90, P ≤ 0.030, S ≤ 0.035, Cu ≤ 0.30, Ni <0.20, quenching of Cr ≤ 0.20 (4) tempering regulate the quenching temperature of 850 ~ 900 ℃, water cooling, and tempering temperature of 550 ~ 650 ° C, quench. Yield strength> 333MPa, tensile strength> 539MPa, to extend the rate δ5> 23% shrinkage of ψ> 57%, impact toughness (impact toughness) aku> 108J/cm2 hardness of 152 ~ 212HB.