In line quenching and tempering has allowed ASCO (Arabian Steel Company) to have higher ductility bar at higher strength levels compared with classic rebar production with substantial reduction in alloy consumption by using heat treatment (thermex) during production proses on production line. QTB (Quenching Tempering Bars) is an alternate means of strengthening long bars by quenching the bars with water and then allowing the bars to self-tempering and hardened case, the process is performed in line with the rolling process, after the finishingarea. The process is stable and controlled, and it's effective on hardness and strength properties on reinforced steel bars The research has concentrate on Thermex and Thermex elements in finishing area of rolling process.