Hot-rolled steel products include steel coils and steel sheets cut from them. The steel coil (roll) can be divided into straight hair rolls and finishing rolls (divided rolls, flat rolls and slit rolls). Hot continuous rolling can be divided into ordinary carbon structural steel, low-alloy steel, and alloy steel according to its material and performance. According to their different uses, they can be divided into: cold forming steel, structural steel, automotive structural steel, corrosion-resistant structural steel, mechanical structural steel, welded gas cylinder and pressure vessel steel, pipeline steel, etc. Hot rolled steel coil is a technical term for metallurgy. Hot-rolled sheet is a kind of smelting material, which belongs to a kind of plate, and its thickness range is generally specified as 1.2~6mm.