Description
A pipe with a cross-section other than round and having four equal-sized faces is called a square steel profile pipe. It has a square cross-section and is used in a wide variety of construction applications, as well as in the creation of metal structures.

A square steel profile pipe is produced by cold and hot deformation (seamless) or by electric welding of a metal sheet bent in a certain position (welded) in accordance with GOST 13663-86 from alloy and carbon steels St2ps, St2sp, St4sp, St4ps, 10, 20, 35, 08kp. According to the type of processing, square pipes are:

processed (heat treatment of the seam and all surfaces);
unprocessed;
galvanized;
non-galvanized.
According to quality, square profile pipes are divided into classes:

A — standardized by mechanical characteristics;
B — standardized by chemical characteristics;
B — standardized by mechanical characteristics and chemical composition;
D — standardized by internal hydraulic pressure.
Methods of manufacturing the product
Seamless square profile pipe is produced on special rolling mills, the blank for its manufacture is a round pipe. The square seam pipe is created from a steel strip (strip) by passing through a forming mill and bending into the desired configuration. The joint that appears in the process is welded by arc welding in a protective environment or by an induction method. The weld and edges are carefully cleaned, the pipe is cut into sections of the desired length and subjected to heat treatment to relieve internal stress that is formed during deformation.

The main advantage of a square steel profile pipe is its low cost and increased strength. It is produced in lengths from 9 to 12.5 meters, depending on the purpose, the wall thickness varies from 1 to 12 mm, and the size from 15x15 to 100x100 mm and more. The weight of one linear meter varies from 0.479 to 4.63 kg. A hollow square profile pipe has the same rigidity as a solid metal square rod of the same size, while the weight of the rolled profile is 40% less. A square profile pipe with thick walls is suitable for load-bearing elements of metal structures.

Scope
Square profile pipes are actively used in the construction of industrial and civil facilities. They are used for the frames of load-bearing structures of administrative, residential, commercial, office buildings, sports facilities and complexes, entertainment centers, hypermarkets, roof trusses and spans of industrial buildings and facilities. It is used to organize suspended passages, overpasses, bridges, flights of stairs, canopies. In furniture production, shaped pipes are used as frames for study tables, chairs, and shelves. They are used to build light structures: canopies, gazebos, greenhouses, summer kitchens, verandas. They are an indispensable element of decorative structures, billboards, signs, and shop windows. In the automotive industry, they make support frames from them, and many elements are used in shipbuilding and aircraft engineering.