Carbon steel structure under normal circumstances are not as heat treatment, and in the supply of state of immediate use. Usually Q195, Q215, Q235 of the quality of scores of low-carbon, welding performance, and plastic, good toughness, a certain intensity, often rolling into sheets, steel, welded steel pipes, used for bridge and building structures and creating general rivets, Screws, nuts and other parts. Q255 and Q275 the quality carbon steel slightly higher scores, higher intensity, plastic, better toughness, welding, usually rolled into steel, steel, steel and manufacturing as well as for the structure of the simple mechanical link, gear, the shaft Day, sales, and other parts.