Frequently Asked Questions

Grade 600 EQR

Our QC laboratory is equipped with Spectrometer, Universal Tensile Strength Machine
and Microscope etc to ensure high grade of products.

- Superior Chemical Properties as compared to the relevant required maximum values of Carbon & Sulphur
- Superior Physical Properties
- Superior UTS (Ultimate Tensile Stress) /YS (Yield Stress) Ratio
- Superior % Elongation
- Better Nitrogen Values

5.5mm to 32mm

Captain 600 EQR can resist upto 600 degree Celsius

Yes, we provide the test report with the consignment


600 EQR is made from C-20 billets, which enhances the intrinsic quality of the bar to withstand load under adverse conditions.

The scientific rib design of Captain 600 EQR provides better gripping for better bonding with concrete.

Captain 600 EQR can resist upto 600 degree Celsius.

Due to low carbon content, bars can be butt or lap welded using ordinary rutile
coated electrodes without pre or post heat treatment.

Rust Guard TMT bar is called a green revolution in steel and Captain Steel India Ltd
manufactured it first in Eastern India.

It is called Rust Guard as this TMT bar provides complete protection from Rust and corrosion due to
the epoxy coating on the bar.

Epoxy coatings cure, whereas paint dries. In addition, when 100 percent solid epoxy
coatings are used, the surface becomes hard and durable, making it highly resistant to
things like chemicals, abrasions, impact, oil and grease, and stains.

No the green colour is not hand painted. It is a fusion bonded epoxy coating on the TMT bar, done by high end machines. Fusion bonded epoxy is basically 100% solid ground fused powder particles
which when heated melt to form a continuous film, the metaloplast membrane. This membrane being non-penetrative protects the steel from attack of oxygen and water molecules and provides
protection from rust and corrosion.

The rib design of Rust Guard TMT bar ensure strong grip with concrete in RCC under fusion bonding conditions. So Rust guard doesn’t slip with concrete, rather has a very strong grip with concrete.

Yes Rust Guard TMT bars can be welded. After welding, patch up coating must be applied on the cut
area. Patch up coating is provided complimentary by Captain Steel on every purchase.

Yes Rust Guard TMT bars are flexible and can be bent.

Rust Guard TMT bars conforms with BIS IS 13620 : 1993 specifications

No, please use cutting machine or hacksaw blade to cut Rust Guard TMT bars.

Please use mandrel for bending Rust Guard TMT bars.

Rust guard TMT bars are manufactured by the following steps:
a. Surface preparation by shot blasting process
b. Heating of rebars (upto 240 degree Celsius) by Induction heating
c. Epoxy coating on rebars
d. Quenching on rebars
e. Testing of the product

German based “Thermex” technology

Yes Captain 600 EQR is manufactured at fully automatic continuous rolling mill which result in excellent dimensional tolerance to set perfect configuration in surface finishing

General FAQ's

Thermo-Mechanically Treated bars, better known as TMT bars, are high-strength
reinforcement bars that have a tough outer surface and a soft inner core. The strength of
TMT bars is controlled by optimising the water pressure to render a soft core and tough
exterior surface, thereby providing optimum strength, ductility and toughness

TMT reinforcing bar has a soft ferrite-pearlite core and a hard martensitic rim. The outer
layer of the steel bar becomes tough and durable due to the drastic difference in temperature brought about by the process of sudden quenching. TMT bars are then subjected to atmospheric cooling to equalise the temperature difference between the inner core and exterior. As it gradually goes through a cooling process, the TMT bar turns into a
ferrite-pearlite mass. The TMT bar has good tensile strength and ductility since the inner
core remains soft.

TMT bars are widely used in general purpose concrete reinforcement structures, bridges and flyovers, dams, thermal and hydel power plants, industrial structures, high-rise buildings,
underground platforms in metro railway and rapid transport system.

The manufacturing process of TMT Bar involves the following steps
Step 1- Manufacturing of billets from raw materials:
Step 2 - Heating, Rolling and formation of reinforced bar:
Step 3 - Quenching:
Step 4 - Self-tempering:
Step 5 - Atmospheric Cooling:

Manufacture of Steel Billets

Billets are rectangular rods which are created by the Continuous Casting Process. In this process,
steel is molten and heated to a temperature of 1700°C. It is subsequently poured into casting
moulds to give the form of billets.

The hot billets are sent to a Rolling / Reduction Mill where the thickness is further reduced and
elongated across three stands – Roughing, Intermediate and the Finishing stands. 


Undesirable property changes might occur in case freshly cast rods are consistently kept at a
higher temperature.
However, this is prevented by passing the bars through a Quenching Chamber where they
undergo Rapid Cooling system and are sprayed with cold water.
This leads to a unique layer called Martensite being formed on the exterior surface of the bar.

Self Tempering

During the cooling down process of the steel bars, the outer core of the bar is at a lower
temperature and the inner core is at a much higher temperature.
The Martensite is further tempered on exposure to air and conduction, which leads to heat flix
being transferred to the outer core from the inner core.
Eventually, the process leads to the formation of Bainite and Martensite rings around the bars.
This helps the bar to achieve higher yield strength. The core remains hot and malleable,
otherwise called austenitic during this phase.

Atmospheric Cooling

The temperature of the inner core of the bars are gradually reduced to room temperature by
passing them through special cooling beds. At this point the differentiation of outer and inner
core becomes cognizable. The bar becomes more weldable and tensile since it has Ferrite- Pearlite structure in the center.
The bars are then tested, bundled, and made ready for despatch.

Earthquake resistant
Enhanced strength combined with high ductility
High thermal resistance
Better malleability
Can be easily welded without loss of strength at places of welding

Quality of material being used Equipment and machinery involved in the self-tempering and quenching process. Rolling mill which gives shape to the material.

- Better bending strength, better ductility, better malleability, better thermal resistance, and better corrosion resistance.
- It saves time in the Reinforcement process
- Reduces the cost of the labour
- Lesser weight, hence, a reduction in transportation cost
- Easy processing since easily bendable without losing strength

- Ease of bending, rebending and reverse bending
- Can be Butt-welded/ Lap welded
- High corrosion resistance.
- No significant changes in strength due to aging.
- Weldability and excellent ductility
- Easy bendability factor
- Ideally suitable for a concrete structure.
- No huge change in quality at high temperatures. 
- The use of high tmt grade rebars ensures around 15-17% savings in steel.
- Low carbon content.
- Percentage of elongation and tensile strength is high, high yield stress, the rate of prolongation is high
- Greater ductility for usage in seismic zones
- Greater resistance to higher temperatures
- Better bendability and greater weldability
- Better corrosion resistance property

Fe-415, Fe-500, Fe-550, and Fe-600 are four different grades of TMT bars produced in
These grade numbers signify the stress level that must be applied to make any
deformation in the bar. More stronger and superior bars have higher grade. According to
their strength and rigidity, the respective grades are given.
Decorative structures like balcony railings etc are made with low graded bars, but for
core building structures like roofs and floors high graded bars are used.
Usually for residential constructions and homes, Fe – 415 is suitable whereas Fe – 600
bars are used for industrial use. For construction of bridges and underground structures,
versatile bars like Fe – 500 and Fe – 550 are preferred.

In 1959, Round bars were used, which led to plain ribbed bars from 1960 onwards. In
1968 came CTD bars (Cold Twisted Deformed) and the next step was TMT bars, which
happened in 1980.

Now, let’s learn a little detail about these different grades of these bars which the TMT bar
manufacturers in India produce –
1. Fe-415 – This grade of TMT bar is perfect choice for homes and residential
construction. They feature higher elongation which makes them absolutely perfect for
building structures in earthquake-prone areas. Due to their anti-corrosion resistant
coating, these grades of bars protect from rust and corrosion
2. Fe-500 – This grade of TMT bar is popularly known for its uses during the
construction of bridges, underground structures and multi-story commercial buildings.
3. Widely used in coastal areas since they are resistant to corrosion
4. Fe-550 – They are slightly better than Fe-500 grade and they are used both for
construction activities which Fe-500 is capable of and also for those projects for which Fe
– 500 is a little unsuitable
5. Fe-600 – This type of TMT grade is generally used for heavy industrial construction
as they require extraordinary strength and hardiness. This grade feature higher tensile
strength than any of the other grades

When iron is oxidised by open air, a layer of oxide is formed which is known as rusting.
Although rusting has no impact on the quality of product, it is quite common since reaction
of air and moisture forming rust is a regular phenomenon. It spreads on the surface
uniformly. Corrosion is a chemical or an electrochemical reaction between an engineered
material and its environment which causes its disintegration. Other compounds are also
formed along with oxides and this leads to the metal surface being unevenly eroded. This is
detrimental to the product quality.

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