Fang Gang: It is solid, bar material. Different from Square Pipes, hollow, belongs to pipes. Steel: A material of various shapes, sizes and properties required by steel ingots, billets or steel materials through pressure processing. Steel is an important material indispensable for national construction and realizing the four modernizations. It is widely used and has a wide variety of varieties. According to the different cross-sectional shapes, steel is generally divided into four categories: profiles, plates, pipes and metal products. In order to facilitate the organization of steel production, ordering and supply and good operation and management, it is also divided into heavy rails, light rails, large steel, medium-sized steel, small steel, steel cold-bent steel, high-quality steel, wires, medium-thick steel plates, thin steel plates, electrical silicon steel sheets, strip steel, Seamless Steel Pipe steel, welded steel pipes, metal products and other varieties. Similar bars include Round Steel, hexagonal steel, and octagonal steel. See National Standard GB/T 702-2008 Hot-rolled steel rod size, shape, weight and allowable deviation
