TMT Bars

TMT stands for Thermo-Mechanical-Treatment. The essential step during the manufacture of TMT bars is the usage of Quenching and Tempering technique, which gives the TMT Bars their strength.

Quenching is the process during which the extremely hot bars coming straight out of the rolling mill are suddenly cooled down with the help of water and air pressure. This cools down the bars from the outside and forms a marten site on the surface of the bar, while the core of the bar remains hot. Tempering takes place when the bar passes out of the quenching or cooling system, when the heat at the core passes out into the surface.
The Quenching and Tempering technique ensures that the core of the bar contains ferrite pearlite, which is has a soft, fine-grained structure. At the same time the technique provides the surface of the bar with tempered marten site, which is very hard. This results in giving the bars high strength as well as ductility.
The bars that pass through this process are called TMT Bars.