Using large-diameter square steel pipes as building columns has better performance than round steel. Using large-diameter square steel pipes in the corners can make the building area very effectively utilized. In terms of steel structure residences and high-rise steel structure buildings, large-diameter square steel pipes are more promising.

According to the different cross-sectional shapes, steel is generally divided into four categories: profiles, plates, pipes, and metal products. According to the different smelting quality of steel, profiles are divided into ordinary profiles and high-quality profiles. Ordinary profiles are divided into large-scale profiles, medium-sized profiles, and small-sized profiles according to the current metal product catalog. Ordinary profiles can be divided into I-beams, channel steels, angle steels, round steels, etc. according to their cross-sectional shapes. Large-scale steel: I-beams, channel steels, angle steels, and flat steels in large-scale steels are all hot-rolled. In addition to hot rolling, round steels, square steels, and hexagonal steels are also forged and cold-drawn.

How to weld large-diameter square steel pipes is a relatively complicated process. Many factories require seamless butt joints, and the joints require no gaps. To ensure strength after butt jointing, a cross rib can be welded in one section of the large-diameter square steel pipe, and a groove can be made at the butt joint of the rectangular pipe to facilitate welding. When butt jointing, spot welding can be done on another rectangular pipe or H-shaped steel to maintain the straightness after butt jointing. Welding is not about the smaller the deformation, the better, but welding that meets the use requirements is excellent welding.

At present, large-diameter square steel pipes are widely used in machinery manufacturing, construction, the metallurgical industry, agricultural vehicles, agricultural greenhouses, the automobile industry, railways, road guardrails, container frames, furniture, decoration, and steel structures.