In sheet production, two different technologies are used, which are called cold rolling and hot rolling. In hot rolling, the output product is called black sheet, and in cold rolling, the output product is oiled sheet (in the next article about oiled sheet we will explain) will be First, with the help of hot rolling process, casting ingots are converted into billets and ingots. Then products such as wire, construction sections, rebar and sheet are produced by forming operations. The cold rolling process takes place at a lower temperature than the recrystallization temperature in order to produce belts and sheets with better dimensional quality and mechanical characteristics than hot rolled products. Sheet production with hot rolling technology means that the raw materials for sheet production are melted at very high temperatures, and during this process, the sheet takes on a matte appearance, and due to its apparent color in the market, the term black sheet is used for it. .