Process involved in making quality TMT bars

Did you ever think of the process involved in making quality TMT Bars?

Thermo-mechanical treatment also known as TMT is a process of making high-strength reinforcement steel bars. Thermo-mechanical treatment in making TMT Rebars exerts its effectiveness by creating a temperature gradient between the hot inner core and cooler outer surface. The special thermo-mechanical processing produces steel which has a special pearlite-ferrite encased in tempered martensite which contributes to TMT bars amazing strength and anti-corrosive properties. Not only are they an economically feasible option but also have the advantage of offering high durability and ductility, compared to conventional steel bars.

Let’s look at the stages involved in the manufacturing of Reinforcement bars

The quality of Rebars can depend on many factors such as quality of material used, rolling mill used for shaping the material, machine or equipment used for quenching and the tempering process.

Sourcing Raw Materials

The first step is obtaining the raw materials such as coal, iron ore, dolomite, and limestone. Iron ore is obtained from iron scraps and selecting the right source of iron ore is critical in the manufacturing of the Rebar. Huge volumes of iron scrap are collected and sorted. The raw materials are then processed using an electric arc furnace or basic oxygen furnace or the modern induction furnace to adjust the composition of the steel. Based on the final composition of the steel, certain chemicals can be added or removed from the metal.

Primary and Secondary Steel-making

The next step is making the steel billets. The molten steel is transferred into a ladle from where it is transferred into a continuous casting process. In this process molten steel is poured into moulds which turn the metal into a long, rectangular form called steel billets. The billet is passed through the rolling mill where the thickness and length of steel is reduced. Next, the billets are transformed into TMT bars of various size and diameter by quenching, tempering and cooling.


When the hot rolled bar leaves the final mill stand (including roughing, intermediate and finishing stands) it is passed through a water quenching system where the water sprays cause the surface of the rebars to cool down and harden rapidly. This makes the outer surface hard and leaves the inner core hot and malleable.


After the Rebars pass the quenching system, the core remains hot and continues to supply heat to the surface. This leads to the tempering of the outer martensitic layer into a structure called “tempered martensite’.


Finally, the TMT bars are passed through special cooling beds to cool down. This makes the core cool down to room temperature.

Always choose the best quality TMT Rebars

TMT is highly preferred in the world of construction. The combination of many unique qualities makes them quite an indispensable construction material. While there are umpteen TMT manufacturers in India, Over the last 50 years, Bharathi TMT stands tall as the manufacturer of the finest quality TMT bars in Kerala. This is supported through world-class manufacturing innovations, new-age logistic systems, a strong dealer network across South India.

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