The hot-rolled steel plate is made of continuous casting slab or blooming slab as raw material, which is heated in a walking furnace, descaled by high-pressure water, and then enters the rough rolling mill. Rolling, after the final rolling, it goes through laminar cooling (computer-controlled cooling rate) and coiling by a coiler to become a straight coil. 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. El seu pes de la bobina és més pesat i el diàmetre interior de la bobina d'acer és de 760 mm