Cold rolling is made of hot-rolled coils as raw materials, which are rolled at room temperature below the recrystallization temperature. The thickness of cold-rolled sheet is generally between 0.1--8.0mm, and the thickness of cold-rolled steel sheet produced by most factories is below 4.5mm. Cold rolling is made of hot-rolled coils as raw materials, which are rolled at room temperature below the recrystallization temperature. The thickness of cold-rolled sheet is generally between 0.1--8.0mm, and the thickness of cold-rolled steel sheet produced by most factories is below 4.5mm. Cold rolling: using hot-rolled steel coil as raw material, after pickling to remove oxide scale, cold rolling is carried out, and the finished product is hard-rolled coil. The plastic index decreases, so the stamping performance will deteriorate, and it can only be used for parts with simple deformation. Hard-rolled coils can be used as raw material for hot-dip galvanizing plants, because hot-dip galvanizing lines are equipped with annealing lines. The weight of the rolled hard coil is generally 6~13.5 tons, and the hot-rolled pickled coil is continuously rolled at normal temperature. The inner diameter is 610mm.Product features: Because it has not been annealed, its hardness is very high (HRB is greater than 90), and its machinability is extremely poor. Only simple directional bending less than 90 degrees (perpendicular to the coiling direction) can be performed. To put it simply, cold rolling is processed and rolled on the basis of hot rolled coils. Generally speaking, it is a processing process of hot rolling---pickling---cold rolling. Cold-rolling is processed from hot-rolled sheets at room temperature. Although the temperature of the steel sheet is heated during the processing, it is still called cold-rolling. Due to the continuous cold deformation of hot rolling, the mechanical properties are relatively poor and the hardness is too high. It must be annealed to restore its mechanical properties, and those without annealing are called hard rolled coils. Hard rolled coils are generally used to make products that do not require bending or stretching.