Thermo Mechanical Treatment (TMT) is the world’s most advanced technology in manufacturing of high quality steel. In this method, mild steel is used. The bars are treated after passing through successive stages of rolling to achieve its final shape. A short, intensive but very precise in-line cooling of the rolled bar is imparted in the Thermex process through a proprietary system. This treatment results in a cooled hardened periphery. On further cooling the bar on atmosphere, a thermal exchange (THERMEX) occurs between the core and cooled outside surface whereby the resultant bar structure is a distinct tempered marten site at periphery and a fine grained ferrite-pearlite structure in the central zone. The Thermex Bar produced by the above Quenching and Self-Tempering process (QST) has unique qualities of desired high strength and toughness combined with excellent ductility with bars having elongation (A5) values of 18% to 25%.