Strength of the bars are carefully controlled by optimizing the water pressure for their pearlitic core and tough surface of tempered marten site, thereby providing an optimum strength, ductility and toughness. 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. TMT Bars are thermo-mechanically-treated through leading world tempcore based technology for high yield strength. The process involves rapid quenching of the hot bars through a series of water jets after they roll out of the last mill stand. The bars are cooled, allowing the core and surface temperatures to equalize. The bar core cools down slowly to turn into a ferrlite-pearlite aggregate. Kamdhenu Limited, Bhiwadi unit has been authorized to manufacture Tempcore TMT under licence agreement.

Standard Size and Weight

 
ISI Standard Ndard WeightIGHT Kg./Mtr. Tolerance Limit % Bansal NSAL TMT Weight IGHT Kg./Mtr. Number of ROD in Bundel
8 0.395 7% 0.385 17
10 0.617 7% 0.595 12
12 0.888 5% 0.870 8
16 1.58 5% 1.55 5
20 2.47 3% 2.44 3
25 3.85 3% 3.83 1
32 9.85 3% 6.31 1
40 6.31 3% 9.85 1

Physical Properties

 
Grade IS: I786 FE: 500 Bansal TMT FE: 500 IS: I786 FE: 500 Bansal TMT FE: 500
Yield Stress N/mm'Min. 500 520 550 560
Tensile Strenght N/mm'Min. 545 590 585 625
Elongation % Min. 12 18 8 12

Chemical Properties

 
Constituent Unit IS: 786 Tolerance as per ISI Bansal TMT Weight
Carbon % Max. 0.30* 0.02% 0.250 Max
Sulphur % Max 0.060 0.005% 0.050 Max
Phosphorus % Max 0.060 0.005% 0.045 Max
S+P % Max 0.110 0.010% 0.090 Max
* For weldable bars, carbon content is restricted to 0.25%.
* Above figures are indicative only.