Cold rolled steel pipe is produced through cold-rolled process. Cold-rolling is at room temperature for a further rolled to a target thickness of the thin plate. And comparison of hot-rolled steel, cold rolled steel plate thickness is more accurate, and the surface is smooth, beautiful, but also has a variety of excellent mechanical properties, especially the processing performance. Because relatively brittle cold rolled coil, is not suitable for processing, so under normal circumstances require cold-rolled steel sheet after annealing, pickling and surface roughness was handed over to the customer. The maximum thickness is 0.1–8.0MM less cold-rolled, cold-rolled steel sheet thickness as most of the factories is 4.5MM less; minimum thickness, width is based on the equipment capacity and market demand is determined for each plant.

Cold rolled steel and hot-rolled steel smelting process does not distinguish, but rather rolling temperature, or rolling end temperature. The final rolling temperature is lower than the recrystallization temperature of the steel material becomes the cold-rolled steel. Easy rolling hot rolled steel, high rolling efficiency, but the oxidation of steel hot rolled condition, the product surface is dark gray bleak. Cold-rolled steel mill power requirements, low rolling efficiency, and rolling process in order to eliminate work-hardening but also for intermediate annealing, so the cost is higher, but the cold-rolled steel bright surface, good quality, can be directly used for processing finished products, especially cold-rolled steel is widely expressed.

Hot-rolled steel coil as raw material, after cold rolling pickling descaling, the finished product is rolling hard volumes, due to the continuous work hardening caused by cold deformation rolling hard volumes of the strength, hardness increased tough plastic index fell. Therefore stamping performance will deteriorate, only for simple deformation of parts. Rolling hard volumes can be used as raw material for hot dip galvanizing plant, because hot dip galvanizing line is provided with annealing line. Rolling hard volume weight is generally from 6 to 13.5 tons, steel coils at room temperature, hot-rolled pickled coils for continuous rolling. An inner diameter of 610mm.