The Original TMT Steel Bar

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With four well-equipped manufacturing units spread across eight acres, Kalliyath is the only brand in Kerala that produces 6mm original TMT Steel bars and also the only brand in India to produce Fe 500 graded 6mm bars with ISI certification. At Kalliyath, each TMT Steel bar is made from the PLC controlled Continuous Linear Rolling Mill in adherence with the BIS quality standards and norms to ensure quality consistency

From ever-increasing infrastructure requirements to landmark constructions to individual homes, there is an exponential demand for reinforced bars in every segment of the industry. The reason why the infrastructure market is now replete with manufacturers, mostly small scale, and TMT Steel bars made without following the necessary BIS instructions. To solve this mounting problem, Kalliyath has always been instrumental in making people understand what a real TMT Steel bar is.

The Process

1

SELECTING THE RAW MATERIALS

Selection of raw materials is the most important factor that determines the quality of a TMT bar. At Kalliyath, steel is produced using high-quality raw materials. These are supplied by world-class suppliers of billets from virgin iron billets, like Vizag, SAIL, etc. Raw materials for making TMT are also manufactured by Kalliyath to maintain consistency in quality.

The raw materials Kalliyath uses have three main advantages
The unique combination
of all chemicals and substances
No decrease in strength
even after reduction
Selected raw materials certified by
BIS for the making of Fe 500 TMT bars
advantages
2

TEMPERATURE OF BILLET

The process utilizes residual heat from the rolling process to attain the desired mechanical properties. Billets, which are heated in the re-heating furnace, are rolled through a series of rolling stands and progressively reduced to the final desired sizes and shapes. In this stage it is vital that the temperature of billet should be 1,200 ℃ . The fully automated furnace makes for precise temperature management. Besides, through controlled firing, it keeps a check on pollution, and promotes environment-friendly production.

Temperature of
billet should be

1,200 ℃

advantages
3

PLC controlled Continuous
Linear Rolling Mill

With the help of computerized process, qualified engineers of Kalliyath passes the 1,200 ℃ billets to the PLC controlled Continuous Linear Rolling Mill. This helps to enhance production speed - 30 meter per second, while processing in 23 passes.

The process is controlled by monitoring devices, in an all mechanized technical operational environment. This enables the production of rebars with perfect shape, uniform thickness and equal standard length. The rolling mill operating in tandem with the continuous casting machine cools the billet temperature to help reduce the material and within 40 seconds, these billets are made into TMT bars


ensuring excellent dimensional tolerance and surface finish. Most of the rolling mills in Kerala have the manual process which takes too much time and lacks the temperature required for processing. This leads to the loss of quality of the TMT bar.

4

Speed, precision and Quality

For reduction, billets are passed through the vast automated high-speed rolling mill units of Kalliyath. Normally, TMT bars needed for gauge are passed only 15 to 19 times. But at Kalliyath, bars are passed 21 to 25 times to ensure uniform size, shape and strength to decrease the production time. Mills that work with manual technology reduce the number of passes which results in the loss of quality, strength and unique shape of TMT bars.

hyd
5

QUENCHING PROCESS

The hot rolled rebar emerging from the finishing stand mill will be of 400 ℃ . These bars are then rapidly cooled by Quenching Process. The Quenching Process with Patent hydromax technology facilitates accurate controlled cooling. A special water spray system converts the surface layer of the bar to a hardened ‘Martensitic’ structure while the core remains ‘Austenitic’. The process pressurizes and deforms the crystal structure of intermediate layers, and simultaneously begins to tamper the quenched layers using the heat from the bar’s core.

6

AUTOMATED COOLING BED

TMT bars that come out after the Quenching Process will be of 250 ℃ . These bars are cut into desired sizes and then passed through Automated High-Speed Cooling Bed. This stage involves normal cooling to room temperature where the ‘Austenitic’ core is transformed to a ductile ferrite + pearlite structure. This finished bar has a microstructure comprising of a tough outer layer of tempered ‘Martensite’ and a ductile core of ‘ferrite + pearlite’. This composite structure gives excellent yield strength to the bar along with superior ductility and weldability. The mechanism of automated cooling bed ensures that the bars are uniformly positioned over the toothed racks. The advanced technology helps prevent the damages caused by the collision of TMT bars and thereby gives a unique uniform strength and shape. But in manually operated rolling mills, labourers do this with a hook. The increased strength and toughness of TMT bars create problems during subsequent manual bending operations. This, in turn, will affect the shape and strength of the TMT bars.

7

STRINGENT QUALITY CONTROL

The quality of dye used has been enhanced, resulting in material consistency. This has also helped to increase the production from 40 to 200 tons, by saving the time of furnace change.

TMT bars made through this process are then sent to specially arranged labs to test the quality and strength by suing the right chemical composition of F500 grade set by BIS.

Also, the sectional weight and strength of each unit of TMT bar is tested every 30 minutes to give customers the best ever. Kalliyath TMT bars have precise, uniform and parallel rib pattern engraved through computer controlled notch making machines, which results in excellent bond strength with concrete. The right combination of chemicals in Kalliyath TMT bars ensure easier and faster welding without preheating. This means stronger and safer weld joints and reduction in wastage during welding at the site. Kalliyath TMT bars are proven to have a higher resistance to cyclic loading conditions and are recommended in earthquake prone areas due to their superior seismic resistant properties. Due to the highly controlled process that ensures a micro-structure with a soft core, Kalliyath TMT bars have excellent bendability, making work easier and faster at construction sites.

8

ENVIRONMENT
FRIENDLY PRODUCTION

At all Kalliyath manufacturing units, the production processes adhere to international environment-friendly standards. This is made possible by the latest technology and advanced equipment that controls pollution and reduces wastage to a large extent.

ENVIRONMENT FRIENDLY PRODUCTION ENVIRONMENT FRIENDLY PRODUCTION
ENVIRONMENT FRIENDLY PRODUCTION
9

SAFETY, A PRIORITY

At Kalliyath production units, safety measures are prioritized for the benefit of the employees. An expert team is always at service to ensure and manage the safety of workers. Kalliyath ensures that its manufacturing units are totally safe by installing protective devices like safety grills and protective gear.
Add to this, regular employee training and rigorous inspections, and you can see safety here is always a priority.

The Tradition of Strength and Flexibility


We’ve made history. Right from being the first TMT bar manufacturer in the state, to the first to bring in automation and several other innovations that set new benchmarks for the industry. For us at Kalliyath it was always about a passion. The passion to create the very best.

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