PADMASREE TMT STEELS PVT LTD., as we are known to our associates has been in the manufacturing of TMT rebar/MS billets since 2004. With having production capacity of 1,68,000 MT TMT bars per annum, 1,05,000 MT MS billets per annum and 6MW per hour gas based power plant capacity, all are under one roof which is located at Devarapalli village.
| Description | TMT |
|---|---|
| Standards | IS1786-2008 |
| Grade | Fe-500, Fe-550 Fe-550D |
| Specifications | 8mm to 32mm |
| Nominal size mm | BIS Standards weight per mtr in kgs | Tolerance | SIRI power rebars weight per mtr in kgs |
|---|---|---|---|
| 8 | 0.395 | +/- 7% | 0.380 – 0.395 |
| 10 | 0.617 | +/- 7% | 0.590 – 0.617 |
| 12 | 0.888 | +/- 5% | 0.860 – 0.888 |
| 16 | 1.58 | +/- 3% | 1.580 – 1.610 |
| 20 | 2.47 | +/- 3% | 0.380 – 0.395 |
| 25 | 3.85 | +/- 3% | 3.860 – 3.900 |
| 32 | 6.31 | +/- 3% | 6.320 – 6.380 |
|
PROPERTY |
MECHANICAL PROPERTIES (Percentage minimum) |
|||||
|---|---|---|---|---|---|---|
|
Fe – 500 |
Fe – 550 |
Fe – 550D |
||||
|
BIS |
SIRI |
BIS |
SIRI |
BIS |
SIRI |
|
|
.2% proof stress / Yield Stress Min, N/Sqmm |
500 |
530 |
550 |
570 |
550 |
560 |
|
Elongation % Min on gauge Length 5.65 ??a- A is cross sectional Area |
12 |
20 |
10 |
18 |
14.5 |
16.5 |
|
Constituents |
CHEMICAL COMPOSITION (percentage MAX) |
|||||
|---|---|---|---|---|---|---|
|
Fe – 500 |
Fe – 550 |
Fe – 550D |
||||
|
BIS |
SIRI |
BIS |
SIRI |
BIS |
SIRI |
|
|
Carbon |
0.30 |
0.25 |
0.30 |
0.25 |
0.25 |
0.20 |
|
Manganese |
NS |
0.60 |
NS |
0.65 |
NS |
0.70 |
|
Sulphur |
0.055 |
0.050 |
0.055 |
0.050 |
0.040 |
0.035 |
|
Phosphorous |
0.055 |
0.050 |
0.050 |
0.050 |
0.040 |
0.040 |
|
Sulphur & Phosphorous |
0.105 |
0.100 |
0.100 |
0.095 |
0.075 |
0.075 |
|
Nominal size of specimen |
Diameter of Mandrel |
|||||
|---|---|---|---|---|---|---|
|
Fe 415 and 500 |
Fe 550 and FE 500 |
Fe 550D |
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|
BIS |
SIRI |
BIS |
SIRI |
BIS |
SIRI |
|
|
Up to and including 10mm |
5ø |
4ø |
7ø |
5ø |
6ø |
5ø |
|
Over 10mm |
7ø |
4ø |
8ø |
5ø |
7ø |
5ø |
SIRI POWER Fe 550D Rebars are thermo Mechanically Treated (TMT) steel bars produced Through advanced HYQST (High Yield Quenching and self – Tempering process)/ QST (Quenching and self Tempering) process. HYQST/ QST process includes hot rolling of the billets in the most modern barmill followed by water quenching, self – tempering and atmospheric cooling. During quenching, the temperature of the rebar drops at a faster rate at the periphery leading to a hard surphase, while the high temperature core gets cooled slowly. The thermal stresses generated during quenching are relieved by the heat released from the core during the next step called self- tempering. Finally atmospheric cooling at the cooling bed leads to a strong casing and a soft core in the rebars giving the significant strength and ductility. The reason behind such unique combination of strength and ductility is that at higher cooling rate, the surface attains a hard phase of steel known as Martensite while the core will soft phases like ferrite and pearlite.
Designing structure with Fe 550D reduces the steel consumption by 12 -15% with optimisation using Fe 550D steel.
Using stronger grade steel means reduction in bar diameter that results in increased bar spacing as fewer rebar`s needed.
Using lesser steel requires less labour which saves on labour cost.
Less time is wasted on placing / tying of bars and less weight on cranes improves construction efficiency.
When the same structure is constructed with 3 different grades of steels, there will be remarkable saving in case of use of Fe 550D.