TMT (Thermo Mechanical Treatment) bars and CTD (Cold Twisted Deformed) bars are both high-strength reinforcement steel bars, but their process of the product is not the same. CTD or twisted bars involves the process of cold twisting while TMT bars involves the manufacturing process of using hot treatment technology.
There are three specific stages involved in the hot treatment of TMT bars which includes quenching, self-tampering and atmospheric cooling. In this process, an intensive cooling is applied in the steel bars as they pass through the Tempcore water cooling system which hardens the surface of the steel bar and as there is no kind of twisting involve in this process and that is the reason the steel bars does not go through any torsional stress which does not create any surface detects and makes it corrosion resistant.
During the manufacturing of CTD bars, they are kept in natural cooling and they are being twisted in the room temperature and because of that the inside grains of the bar turns into the crystal, are then crushed which provides the bar with the required strength. After steel rods gets cooled twisting is done. The method of twisting the rods generally increases the tensile strength of the rods but at the same time it also negatively affects the ductility of the steel bar and breaks the protective blue oxide which makes the CTD bars free to corrosion.
Group Nirmal is one of the leading construction steel manufacturers with their brand name “TRICON”, is a high strength structural steel bar, which lowers the diameter of reinforcement bars without affecting the strength of the reinforcement which leads to significant savings. Our high strength deformed bars conforming to IS 1786 (1985) of Grade Fe550 corresponding to DIN: 488 & B.S. 4483 are manufactured using the well-established and well-defined technology of simultaneous cold rolling and cold ribbing. TRICON TM bars can be used as a general-purpose concrete reinforcement in all types of reinforced concrete structures. It can be used in combination with any grade of concrete-like M-15, M-20 & M-25 which ensures economy, better functional aspects, structural safety and strength.