Know Your TMT Bars!
Steel

Know Your TMT Bars!

The Indian infrastructure story has been told and retold with great vigour. However, not much is said about the component that provides inherent strength to infrastructure: TMT bars, a neglected segment where more research and analysis are required. With lower awareness, unorganised and poor-qu...

The Indian infrastructure story has been told and retold with great vigour. However, not much is said about the component that provides inherent strength to infrastructure: TMT bars, a neglected segment where more research and analysis are required. With lower awareness, unorganised and poor-quality players enjoy a larger market share. After a detailed analysis, FIRST Construction Council (FCC) has listed the ones with the best mettle to help end-users take an informed decision.With the TMT bar industry dominated by unorganised local manufacturers, are we really getting quality products? To know this, we need to understand the structure and manufacturing processes.Understanding the industry structureEarlier, there was a clear-cut bifurcation based on the manufacturing process followed and ‘primary’, ‘secondary’ and ‘integrated’ producers based on a government notification dated April 24, 2015. Based on this categorisation, primary producers held a 45-per-cent market share while secondary producers held a 55-per-cent market share. However, this classification was withdrawn by the Ministry of Steel vide a notification dated May 12, 2016. It stated that no steel producer would be classified as an integrated, primary or secondary producer. According to the notification, the process route adopted for ironmaking and steelmaking with or without rolling/finishing operations as they may be and product mix would be listed with Joint Plant Committee (JPC), Kolkata. However, the listing would be purely for statistical purposes and would have no bearing on the quality of steel produced. The onus is thus on users to ascertain the quality of the steel products to be procured, as per relevant standards. Here, the role of FCC becomes important as we try to ascertain the quality based on the standards.Today, there are two major commercial processes for making steel: Basic oxygen steelmaking, which has liquid pig iron from the blast furnace and scrap steel as main feed materials; and electric arc furnace (EAF) steelmaking, which uses scrap steel or direct reduced iron (DRI) as main feed materials.Primary steel is acquired from a steelmaking process known as the converter process. Here, iron ore is converted into steel. This process uses pig iron from the blast furnace. Primary steelmaking has two methods: BOF (basic oxygen furnace) and the more modern EAF (electric arc furnace) methods. Secondary steel is usually made after adding some alloying elements to primary steel. This steel is made by melting scrap or sponge iron and sometimes a mixture of both using the induction route. Prime difference: It’s the process that matters!To differentiate between a quality TMT bar and a poor one, one needs to comprehend the basic difference. For that, one has to understand the detailed process of manufacturing steel – rather, the ideal method to manufacture a finished product. See the chart on the ‘Steps followed for TMT bar manufacturing’, which will help understand the various stages and methods of steelmaking and finished steel.Process: What’s missing? Rather, what’s present?As per the simplified version of the process, the first step is to select the right kind (quality) of raw material. If the base constituent of any manufacturing process is of low grade, the end product is not expected to be any better. So, the differentiation begins in the first step itself. Players following the blast furnace method use iron ore, coking coal, limestone, pellets and sinter. But the players following the induction method use DRI scrap. While scrap is already low grade, DRI is highly susceptible to oxidation and rusting if left unprotected, and is normally quickly processed further to steel. The bulk iron can also catch fire as it is pyrophoric. Unlike blast furnace pig iron, which is almost pure metal, DRI contains some siliceous gangue, which needs to be removed in the steelmaking process. Samples, tests and analysis – focus on quality playersWe took different diameter samples of similar grade (Fe500 and FE550 in some cases). Classification was done on diameter basis. In the retail segment, TMT bars of 10, 12, 16 and 20 mm are widely used; hence, we decided to present strong players amid this range. To be specific, there are four players each with 10 mm and 12 mm dia; 10 players with 16 mm dia; five players in the 20 mm segment; and around six players with samples of 25 mm dia. Further, we have four players with 32 mm dia and, last, one major player with 36 mm diameter. We have further added the other diameter rebars as well as we have an institutional readership and, hence, the analysis would be done for one and all. (Turn to the next page for the test results.)ConclusionWe would like to conclude by saying that as TMT bars provide inherent strength to all structures, it is vital for end-users to be aware of their physical and chemical properties. Rather than focusing on short-term benefits arising from the pricing mismatch of primary and secondary players, one must focus on the longevity of the structure. Quality will assure longevity; thus, ensure that you buy your TMT bars from a trustworthy manufacturer.

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