TMT Steel :

FF-STEEL’s most significant and prominent contribution to the Pakistani steel as well as construction industry the introduction of Thermo-Mechanically-Treated (TMT) Steel Bars. Worldwide the advent of TMT Steel Bars has heralded a new era of economy in the construction industry. Round plain steel bars ruled over this industry up to the sixties, while TOR steel took over scene in the seventies and maintained its supremacy till the nineties. Recently the construction industry in the world has seen an extensive use of TMT Steel, thereby ushering in greater economy and longer life for RCC structures. In many countries, the use of TMT Steel is mandatory in seismic zones 2 and above. 

Under Thermo-Mechanical-Treatment of steel bars, the bars are made to pass through a specially designed water cooling system, where they are kept for such a period that the temperature of the outer surface of the bars drops considerably, while the core remains hot. This rapid quenching of the steel bars creates a temperature gradient in the bars. When the bars are taken out of the cooling system, the heat flows from the core to the outer surfaces causing further tempering of steel bars, thereby helping them in attaining higher yield strength of steel with better elongation. 

Below are the characteristics of TMT Steel which makes it superior to the current deformed Steel Bars being used in Pakistan:

Higher Elongation:
Grade 60 TMT Steel Bars have an average elongation of 18%, compared to the 10% elongation provided by the current Grade 60 bars available in Pakistan.

Corrosion Resistant:
The controlled water-cooling of the bars (combined with the low carbon content) prevents the formation of coarse carbides, which has been cited as cause for the corrosive nature of the common re-bars.


Excellent Weld-ability:

Due to low carbon content, TMT Steel Bars are more easily welded compared to common re-bars.

Higher Heat Resistance:
Due to the quenching process, an outer layer of tempered marten-site structure is formed which act as shield to heat. The mechanical properties of common Steel Re-bars begin to deteriorate at temperatures of 300 degrees centigrade where as those of the common TMT Steel Bars begin to deteriorate at 600 degrees centigrade.

Economical:
The Grade 75 TMT Steel Bars are also highly economical for Seismic Zone-1 as despite being much more superior to the non-TMT Steel Bars, there is only a nominal price differential. Buildings and structures if properly designed for Grade 75 TMT Steel Bars (with 18% elongation) can save up to approximately 15 to 20% of steel.

Bend-ability:
TMT Steel Bars exhibit very high bend-ability and also re-bend-ability with internal diameter of 1D and 4D respectively, where D is the diameter of the Bar. It is easier to work with these TMT Steel bars due to easy bend-ability.

TMT bars are much superior to the conventional TOR and deformed steel bars by virtue of their various engineering properties and can be used for residential buildings, bridges, dams, industrial establishment and all types of concrete reinforcement purposes.

FF-STEEL has the capability of making TMT deformed steel bars of the following sizes:
> Grade 60 (ASTM 706), 10 mm to 40 mm (60,000 psi)
> Grade 75 (ASTM 615), 10 mm to 40 mm (75,000 psi)
> BS 4449:2005 Grade 500, 10 mm to 40 mm (71,000 psi)

FFF-STEEL has the capability of making TMT plain steel bars of the following sizes:
> Grade 60 (ASTM 706), 10 mm to 40 mm (60,000 psi)
> Grade 75 (ASTM 615), 10 mm to 40 mm (75,000 psi)
> BS 4449:2005 Grade 500, 10 mm to 40 mm (71,000 psi)

Chemical Properties (Reference Standard BS 4449:1997)
Grade
C (Max.)
Mn (Max.)
Si (Max.)
P (Max.)

S (Max.)

FF-Grade-60
0.25
CE = 0.42
0.35
0.005

0.05


Physical Properties (Reference Standard BS 4449:1997)
FF-BH-24
465
495
18
;