In this research, the effects of different cooling conditions after hot rolling in Stelmor conveyor line on the mechanical properties of a commercial high carbon steel wire rod are investigated. By opening and closing the lids, turning on and off the fans in Stelmor system, an air patenting process is performed on a commercial high carbon steel to improve its mechanical properties and ductility. The wire rods produced in different cooling conditions are investigated by tensile test, metallography and image analyzing. The optimum cooling condition required for high strength and ductility are evaluated. Moreover, the relationships between yield stress, UTS and fracture stress, and interlamellar spacing are derived. Also, the uniformity of the distribution of proeutectoid ferrite is measured in different cooling conditions and its effect on the ductility is discussed.