Thermo Mechanically Treated (TMT) bars have gained immense popularity in the construction
industry due to their high strength, ductility, and earthquake resistance. TMT bars are the most
widely used reinforcement bars for construction purposes in India. In this article, we will discuss the
process of Thermo Mechanical Treatment, the full form of TMT, and the difference between TMT and
TMX bars.
What is Thermo Mechanical Treatment (TMT)?
Thermo Mechanical Treatment (TMT) is a process in which hot rolled steel bars are subjected to a
rapid quenching process, followed by reheating, and then finally cooling in open air. This process
alters the microstructure of the steel, which results in enhanced strength and ductility. TMT bars are
produced using a combination of heat treatment and mechanical deformation. This process helps in
producing a high-strength, ductile, and weldable steel bar.
Process of Thermo Mechanical Treatment
The process of Thermo Mechanical Treatment involves the following steps:
1. Hot Rolling: The first step in the TMT process is hot rolling. In this step, steel billets are
heated at a very high temperature and are then passed through a series of rolling mills. This
process helps in giving the steel bars their desired shape and size.
2. Quenching: After the hot rolling process, the steel bars are rapidly quenched in water. This
process helps in cooling the bars at a very high rate, which results in the formation of a hard
outer layer and a soft inner core.
3. Reheating: After the quenching process, the steel bars are then reheated to a temperature
between 600-700°C. This process helps in removing the internal stresses and making the
steel bars ductile.
4. Cooling: After the reheating process, the steel bars are cooled in open air. This process helps
in the formation of a uniform microstructure, which gives the steel bars enhanced strength
and ductility.
Full Form of TMT
The full form of TMT is Thermo-Mechanically Treated. TMT bars are produced by subjecting hot
rolled steel bars to a rapid quenching process, followed by reheating, and then cooling in open air.
TMT bars have a unique combination of strength and ductility, which makes them ideal for use in the
construction industry.
Difference between TMT and TMX Bars
TMT and TMX bars are both types of reinforcement bars that are widely used in the construction
industry. However, there are some differences between the two types of bars. The main difference
between TMT and TMX bars is the process of production. TMT bars are produced using a
combination of heat treatment and mechanical deformation, while TMX bars are produced using
only mechanical deformation.
Which is Better - TMT or TMX?
TMT bars are preferred over TMX bars due to their enhanced strength and ductility. TMT bars have a
unique combination of strength and ductility, which makes them ideal for use in the construction
industry. TMT bars are also more resistant to earthquakes, which makes them an ideal choice for
construction in earthquake-prone areas.
Advantages of Thermo Mechanically Treated (TMT) Bars
1. Enhanced Strength: TMT bars have a high yield strength, which makes them ideal for use in
construction.
2. Ductility: TMT bars have a high ductility, which means that they can be easily bent and
twisted without breaking.
3. Corrosion Resistance: TMT bars are highly resistant to corrosion, which makes them ideal
for use in marine environments.
4. Weldability: TMT bars have good weldability, which makes them easy to use in construction.
5. Earthquake Resistance: TMT bars are more resistant to earthquakes,