Cold rolled sheet (English name: cold rolled sheet) is made of hot rolled coil as raw material, and is rolled at room temperature below the recrystallization temperature. Since it is rolled at room temperature, no iron oxide scale is produced. Therefore, the surface quality of cold rolled sheet is good and the dimensional accuracy is high. In addition, after annealing, its mechanical properties and process properties are better than those of hot rolled thin steel sheet. In many fields, especially home appliance manufacturing, anti-theft door panels, filing cabinet materials, enamel materials, barrel materials, writing boards, stamping parts, automobile manufacturing, electrical products, etc., it has gradually replaced hot rolled thin steel sheet. Cold rolled products can be produced in the form of continuous annealing (CA) or intermittent annealing (BA).