Medium carbon steel wire uses alloy steel with a carbon content of 0.25%-0.60% as the base material. Through the coupling of hot rolling control, spheroidizing annealing softening and cold drawing deformation strengthening, it achieves a precise match of strength (tensile strength 650-980MPa) and toughness (impact absorption energy ≥25J). The hardness HV180-280 is 1.5 times higher than that of low carbon steel, and the tempering softening temperature is above 350°C. Its core value lies in the balance of strength, ductility and cost, and its adaptation to high fatigue conditions - it can be tempered into high-load elastic components such as automobile suspension springs and agricultural machinery torsion bars, and can also be processed into M12-M30 high-strength bolts, gear transmission shafts and other impact-resistant fasteners after quenching and tempering, combining economy and durability.