Well, It’s an important question often asked in the interview. There are TMT 500w, TMT 400w, etc steel bars available in the market.
TMT means Thermo mechanically treated which is the process of manufacturing steel bars.
TMT 500W is a type of TMT bar that is highly suitable for all kinds of construction needs.
The number 500 here indicates the yield strength of the bar. This is measured in pascals and indicates that the yield strength of these bars is 500 pascals.
The ‘W’ indicates that these bars are weldable. To be weldable steel bars need to be more ductile. Higher ductility allows the bars to be easily welded.
1 Mpa= 145 psi,
so 500 x 145= 72500 psi = 72.5 ksi or 72 Graded rod.
Here, 72500 is the yield strength of the bar. If the yield strength is exceeded the rod will fail in tension which will result in structural failure.
What Is TMT?
In TMT technology, steel bars are passed through a water cooling system where these are kept for such a period that the outer surface of bars becomes cool while the core remains hot. This 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 surface causing further tempering of steel bars thereby helping them in attaining a higher yield strength.