A complete guide to steel TMT bars for construction

TMT steel bars are known for their strength, versatility, and ductility, it is used in a wide range of construction projects due to their heat and corrosion-resistant properties. 

Steel TMT bars for construction are preferred by industry specialists worldwide to improve speed and productivity. Also known as the Thermo Mechanically Treated Steel, these bars have a hard outer surface and a soft inner core to ensure maximum strength.

The TMT bars are manufactured under a special process known as Thermo Mechanical Treatment. 

Manufacturing involves five major steps: 

1. Extraction

The first step involves extracting iron from raw materials, such as coke, flukes, and iron ore. These materials are kept in a molten state and subjected to pre-treatment in a converter. This step converts the molten materials into steel. Then, the steel is transferred to a casting machine to produce 130 mm2 billets. 

2. Heating and rolling 

The casted steel billets are heated to 2191 F and reshaped into the final billets with optimal size and shape. Then, the reinforced bar passes through rolling mill stands before subsequent steps.

3. Quenching 

The hot bar from the rolling mill stand is instantly quenched to prevent phase transformations. The undesirable phase transformation will affect the composition and structure of steel bars. Quenching minimizes the time frame to avoid such reactions by imposing a sudden change in this temperature. This change improves the tensile strength of the bars with a toughened outer surface. 

4. Self-tempering 

In this step, the steel bars get a temperature gradient across their cross-section right after leaving the quenching box. As a result, the outer surface gets a high-temperature heat flow and gets the right tempering. This step also gets a structure known as tempered Martensite with Martensite and Bainite intermediate rings. 

5. Atmospheric cooling 

The steel bars undergo atmospheric cooling to equalize the soft inner core and hardened outer surface. When completely cooled down, the austenitic core transforms into a Ferrite-pearlite structure. This also gives the TMT steel bars the desired tensile strength and elongation capacity. 

The specific Thermo Mechanical Treatments ensure the unmatched strength, flexibility, and utility of TMT bars. Therefore, they are widely used in many construction projects. 

The common applications of steel TMT bars for construction Include:

• High-rise buildings 

High-rise buildings are basically tall structures that can be used as offices, residential homes, or even hotels. Steel TMT bars ensure the necessary strength and durability for these high-rise buildings. Most important, the shock absorption properties of these bars can protect these buildings from natural disasters. 

• Residential constructions

The best use of TMT steel bars is home construction. Every home is a huge financial commitment for the owner. Hence, they want the building to be reliable and long-lasting. TMT bars with their corrosion and heat resistant properties can ensure optimum protection for houses. Especially, more and more residential constructions have started to use TMT bars in recent times. 

• Industrial projects 

The high-grade standards of TMT steel bars are still unmatched in industrial constructions. It has been used in projects, such as factories, manufacturing hubs, large units, and warehouses. Because of its ideal flexibility, contractors can also design complicated industrial structures with TMT bars. 

• Bridges and flyovers 

Another significant use of steel TMT bars for construction is bridges and flyovers. Contractors can extend the lifespan of these structures by using TMT steel bars. As cited before, the shock absorption properties of these bars make them an ideal component in this type of project. Moreover, the tensile strength of TMT rods makes them indispensable for highway constructions as well. 

• Power plants 

Dams and power plants are massive structures demanding strength and durability. Such properties are synonymous with TMT steel bars. Contractors can purchase the steel bars from a reliable bar to justify the scale requirements of these projects. Additionally, the structures are safeguarded from fire, corrosion, and natural disaster risks. 

Why TMT steel bars are used for construction? 

At this point, one may argue that there are other types of steel bars available in the market as well. Types like HYSD and TOR rods can also be preferred for construction projects. But, in comparison, steel TMT bars for construction edges both HYSD and TOR in terms of strength, flexibility, and durability. The hardened crystalline exterior and lack of defects in the surface make TMT bars an industry standard for construction projects. 

On top of that, here are some other reasons to consider TMT steel bars: 

• Malleability

TMT steel bars are extremely malleable. Their great flexibility allows them to acquire different shapes to suffice the requirements. They can be hammered, pressed, or bend into a variety of shapes without breaking. In short, the TMT bars can take on a shape without deforming under compression. 

• Anti-Corrosion 

HYSD and TOR rods corrode when exposed to chloride ions. TMT steel bars manufactured with Thermo-Mechanical treatment offer superior corrosion resistance properties. The lack of residual stress also increases the corrosion resistance of these bars. Hence, they are suited for projects in high humidity regions and coastal areas. 

• Cost-effective

Most importantly, Steel TMT bars are highly cost-effective. Contractors can also reduce further expenses on transportation and management due to the superior ductility of these bars. 

Build a strong future 

iSteel Brings value to its customers with a wide variety of high precision-engineered steel TMT bars for construction. Our state-of-the-art casting and machining centers allow us to offer unrivaled structural grades to domestic and international standards.