It is used in the machine building industry and other machine industries, where products with different cross-section shapes and sizes are made by means of moulds of different shapes, the variety of shapes and sizes allows it to be used in a wide range of fields. Advanced cold drawing technology can make the surface of the product become smooth and bright, and the material can be saved a lot. The surface heat treatment of square steel tube is a process which only heat-treated the surface of square steel in order to change its microstructure and properties. Among them, surface quenching is a common method of surface heat treatment. Surface hardening of special-shaped square steel is the process of quenching only the surface layer of the workpiece. The aim is to obtain high hardness and wear resistance on the surface of the workpiece, while the center part maintains good plasticity and toughness, in order to increase its torsion, bending, stress or in friction, impact, contact stress and other working conditions under the service life. The surface quenching of square pipe does not change the chemical composition of the surface of the work piece, but adopts the rapid heating method, which makes the surface layer of the work piece rapidly austenitizing, and makes the center part still under the critical point, and then the surface of the square steel is hardened. According to the different heating methods, the surface hardening methods mainly include induction hardening, flame hardening and contact resistance hardening. At present, there are many applications in the production of inductive fire. When the square tube is deformed, it must first correct the angular deformation, and then straighten out the area of the bending deformation. The home guide to correct the deformation can be made into a 90-degree angle concave-convex die first, and then it can be corrected by the mechanical pressing method. Some parts of the angles will deform and can be straightened together, when the angle is large, hit it with a hammer to make the angle 90 degrees. If the angle is small, use an angle hammer or a hand hammer to expand the angle to 90 degrees. The bending of the deformation needs to be placed on the top of the brackets and then according to the length to beat, is required to be accurate and stable.