1. Square tube introduction: It is a hollow square section with a square section shape and size made by hot-rolled or cold-rolled galvanized steel strip or galvanized coil as the blank, cold-bent and formed by high-frequency welding. Section steel pipe; or galvanized square rectangular pipe made of cold-formed hollow steel pipe prepared in advance and then processed by hot-dip galvanizing.

2. Square tube production process: It is divided into hot-dip galvanized square tube and cold-dip galvanized square tube. It is precisely because the processing of these two galvanized square pipes is different that they have many different physical and chemical properties. In general, they have many differences in strength, toughness and mechanical properties.

3. Square tube processing classification: It is a square tube made by welding steel plate or steel strip after crimping, and on the basis of this square tube, the square tube is placed in a hot-dip galvanizing bath after a series of chemical reactions A square tube formed again. The production process of hot-dip galvanized square pipe is relatively simple, and the production efficiency is high, and there are many varieties and specifications. This kind of square pipe requires very little equipment and funds, and is suitable for the production of small galvanized square pipe manufacturers. But in terms of strength, the strength of this steel pipe is much lower than that of seamless square pipes.

Fourth, the use of common sense of the square tube: the square tube is galvanized, so the application range of the galvanized square tube has been greatly expanded compared to the square tube. It is mainly used for curtain walls, construction, machinery manufacturing, steel construction projects, shipbuilding, and solar power support.

Fifth, the function of the square tube: galvanizing has stronger protective effect and strong corrosion resistance. The entire structure is made of zinc to form a dense quaternary crystal, which forms a barrier on the steel plate, thus effectively preventing corrosion factors from penetrating. The corrosion resistance comes from the strong protective function of the barrier layer of zinc. When zinc is used for sacrificial protection on the cut edges, scratches and scratches of the coating, zinc forms an insoluble oxide layer and exerts a barrier protection function.

6. Calculation of theoretical weight per meter of square tube: 4*(side length-thickness)*thickness

Among them, the side length and wall thickness are in millimeters, and the values are directly substituted into the above formula, and the result is the weight of the square tube per meter, in kilograms. For example, for a square tube of 30 x 30 x 2.5 mm, the weight per meter can be calculated according to the above formula: 4 x 2.5 x (30-2.5) x 7.85=275 x 7.85=2158.75 grams, which is about 2.16 kg. When the wall thickness and side length are in millimeters, 4 x wall thickness x (side length-wall thickness) is calculated as the volume of a square tube per meter length, in cubic centimeters, multiplied by the specific gravity of iron per cubic meter The centimeter is 7.85 grams, which is the weight of each square tube in kilograms.