Square pipe is a form of square pipe, that is, the steel pipe with equal length. It is Q235 hot-rolled or cold-rolled strip or coil as the base material after cold bending forming and high-frequency welding made of square section shape and size of the steel.

　　Next, let me introduce some knowledge about the preservation method of the square tube by Xiao Bian.

　　First of all, we should choose a suitable site or warehouse for the storage of square pipes, should be selected in a clean, well-drained place, should not be stored with acid, alkali, salt, cement and other corrosive materials piled together with the other pipe.

　　Secondly, we should pay attention to stacking when storing square pipes. Under the condition of ensuring safety, we should pay attention to three key points of stacking bottom: cushion height, firmness and smoothness.

　　Hardness is a pointer to measure the hardness and hardness of metallic materials. At present, the most commonly used method for measuring hardness in production is to introduce the specifications and characteristics of the square tube with the lowest increment speed by pressing hardness method and many machine parts which work under cyclic loading. It is a square tube with the specifications and characteristics. The seamless square tube is formed by extrusion of the seamless round tube. Mechanical properties of square pipes 1. Performance index analysis of square pipes - plastic plasticity refers to the introduction of specifications and characteristics of square pipes expected to increase efficiency under load, specifications and characteristics of square pipes welded to form circular pipes, and the ability to produce plastic deformation (permanent deformation) without damage. The performance index analysis of 2. square tubes hardness hardness is a pointer to measure the hardness and hardness of metal materials. At present, the most commonly used method to measure hardness in production is to introduce the specifications and characteristics of the lowest increment square tube by indentation hardness method. It is a kind of name for square tube. The specification and characteristics of smooth global flowing square tube are introduced. Under this condition, parts will produce fatigue. Performance index analysis of 4. square tubes - impact toughness