What is TMT rod?

Answer 1

Thermo Mechanically Treated (TMT) rods are manufactured using the 'Quenching & Tempering' (Q & T) technology. A contemporary technology, it allows the production of rods to be on par with international standards. Once the steel bar is rolled, it is made to pass through heat treatment over three successive stages. In the first stage of 'Quenching', intense water quenching is executed on the periphery while the core stays unchanged, leading to a martensitic surface and austenitic core. Subsequently, the bar leaves the quenching box to undergo a process of 'Self Tempering' wherein heat from the austenitic core flows to the tempered martensitic surface. In the final stage of 'Atmospheric Cooling' that takes place on the Cooling Bed, the austenitic core is transformed into ductile ferrite-pearlite structure. The end result is a fine combination of a strong outer rim (tempered martensite) and a ductile core (ferrite-pearlite), thereby imparting strength as well as ductility. After the quenching process, the rods are cut to desired sizes with the Shearing machines and transferred to the Cooling Bed wherein they are cooled to get the defined structure. As opposed to the conventional rods that are subjected to cold twisting, TMT rods have high strength, greater yield & elongation, uniform micro structure, toughness, ductility and weldability. They also bond better with cement concrete mix. Hence they are equipped with the requisite properties to provide strength to structures for enduring natural hazards.