Standard Classification of square tube production by producing sub-standard: GB square tube, the standard square tube, inch square tubes, American standard tube, square tube European standard, non-standard square tube. Section by section shape classification square tube shape classification: (1) simple square section tube - square pipe, rectangular square tube (2) the complexity of the pipe sections - flower-shaped tube, opening shaped pipe, corrugated pipe, shaped square tube. Identification of square tube: With economic development 80 * 80 galvanized pipe, counterfeit products appearing on the society more and more, in order to prevent the purchase of square tube 90 * 90 galvanized pipe, let themselves deceived, then we need to know a little about how to determine the authenticity of the pipe: "We can be judged 75 * 75 galvanized square tube through the surface smoothness and flatness observation square tube, if the pipe surface relatively flat, square tube is able to reflect this is good, on the contrary, if the surface is not so smooth, and the size and thickness of not standardized, it may reflect the square tube is inferior product. "85 * 85 galvanized square tube _ Galvanized Vincent Fang (certified) _ galvanized square tube provided by the Tianjin Steel Pipe Co., Ltd. Rong thousand. 1000-Tianjin Steel Pipe Co. (www.tjqrgg.com) (www.tjqre.com) is Tianjin, steel leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the 1000-pipe leading the staff warmly welcome all inquiries negotiations to create the 1000-pipe a better future. You can also access (www.tjqre.com/supply_details_44428795.html), for more information about the company.