The term steel bars, also referred to as merchant bars, encompasses a wide variety of steel long products with different cross sections, for example, rounds, squares, flats, angles and T-sections. The steel grades used for merchant bars are most often weldable, low-carbon constructional steels with an iron content of 98% or more.
Steel bars are usually manufactured through continuous casting of melted and refined steel to billets which can be square or round. After cooling, the as-cast billets are reheated and hot rolled in a continuous multi-stand bar mill to the requisite section and dimension; in order to save energy, some steel plants have hot transfer between the billet caster and the reheating furnace. After cooling, the rolled bars are cut to length and bundled. Non-symmetrical shapes like angles require straightening before they can be bundled.
Merchant bars find use in a multitude of applications in building construction, mechanical engineering and in the energy and transport segments. In many applications, an example being shipbuilding, bars (for example, angles, T:s and flats) are welded to plates and sheets in order to impart stiffness. As with other steel products, bars used in machines and constructions can at the end of their useful life be recovered and recycled to 100%.