It is extremely important to use high grade steel in a construction of a house. The steel structure used in the construction should be of superior seismic resistance properties.
If you are going to build a residential house, here is some information which may be useful to give basic ideas about steels.
To create a concrete structure to bear all kinds of load and stresses, steel reinforcement/strengthening is used. This steel reinforcement is generally used in the form of bars or rods.
Bars are available in cold twisted deformed bars or TMT bars. TMT is short form of Thermo Mechanical Treatment, and is the latest technique.
Different grades of bars are available, like grade Fe 415, grade Fe 500 etc. Here, 415 and 500 indicate stresses of 415 N/mm2 and 500 N/mm2 respectively. Most commonly used is grade Fe 415.
Some companies produced TMT bars with low carbon levels than specified to get excellent ductility, high bendability and superior weldability. Like Fe 415 grade bars details from TATA TISCON is as under.
| Chemistry | Unit | IS:1786 | TATA TISCON* |
| | | Fe 415 | |
| Carbon | % | 0.03**max | 0.17-0.24 |
| Carbon equivalent (C + Mn/6) | % | - | 0.38 max |
| | % | 0.060 max | 0.050 max |
| Phosphorous | % | 0.060 max | 0.045 max |
| S & P | % | 0.110 max | 0.090 max |
| Nitrogen | ppm | - | 100 max |
| *(Typical Values for 90% of heats) | |||
| *(In case of weldable bars the carbon content should be 0.25% max) | |||
Ductility is the property of metal which permits it to be reduced in cross sectional area without fracture. Bend tests are carried out to ensure that a metal has sufficient ductility to stand bending without fracturing. Due to lower carbon content, it has better welding capability. Although, a number of factors affect weldability including chemistry, surface finish, heat-treating tendencies, etc.
Some companies have brought TMT and corrosion resistant steel (CRS) bars with added features.
Bars are available in the size range of 8,10,12,16,20,22,25,28,32,36, and 40 mm. For general house constructions, bars of diameter 6 to 20 mm are used.
Here are some standard sizes and useful data of TATA TISKON products.
| Section (mm) | Nominal weight (kg/meter) | Nominal length (Mts/MT approx) |
| 8 | 0.395 | 2531 |
| 10 | 0.617 | 1620 |
| 12 | 0.888 | 1126 |
| 16 | 1.58 | 633 |
| 20 | 2.47 | 405 |
| 25 | 3.85 | 260 |
| 28 | 4.83 | 207 |
| 32 | 6.31 | 159 |
| 36 | 7.99 | 125 |
| 40 | 9.85 | 102 |
More information on:
http://www.buildnova.com/buildnovav3/productcatalogue/SteelBrocures/TataSteel.htm
http://www.askacc.com/reinforcement.asp
