The hot-rolled precision steel pipe is made of continuous casting round tube billet slab or pre-rolled slab as raw material, heated in a walking furnace, descaled by high-pressure water, and then enters the rough rolling mill. , implement computer-controlled rolling, and after final rolling, it is coiled by laminar flow cooling and coiling machine to become straight hair rolls. The head and tail of the straight hair curler are often tongue-shaped and fish-tail-shaped, with poor thickness and width accuracy, and the edges often have defects such as wave shape, folded edge, and tower shape. The coil weight is heavier, and the inner diameter of the steel coil is 760mm. After the straight hair coil is processed by cutting head, tail cutting, edge trimming and multi-pass straightening, leveling and other finishing lines, it is then cut or re-coiled to become: hot-rolled steel plate, flat hot-rolled steel coil, longitudinal Tape and other products. If the hot-rolled finishing coil is pickled to remove the oxide scale and oiled, it becomes a hot-rolled acid-washed coil.