Description
Steel Square Profile Pipes are hollow square cross-section structures manufactured by cold or hot forming from steel strip with subsequent welding. Widely used in construction and mechanical engineering due to high rigidity and optimal strength-to-weight ratio.
Production Technology

The manufacturing process includes several stages:
1.    Strip Preparation: Steel strip is uncoiled, straightened, and cleaned.
2.    Forming: In forming stands, the strip is gradually bent into a round pipe.
3.    Welding: The edges are joined by HF or laser welding.
4.    Profiling: The round pipe passes through rolls forming a square cross-section.
5.    Cooling and Calibration: The pipe is cooled and calibrated to achieve precise dimensions.
6.    Cutting: Cut to measured lengths.

Characteristics and Assortment
•    Cross-Section Sizes: from 10×10 mm to 400×400 mm.
•    Wall Thickness: from 0.8 mm to 20 mm.
•    Length: measured (6-12 m) and non-measured.
•    Materials: carbon, low-alloy, stainless steels.
•    Manufacturing Accuracy: increased and ordinary.

Advantages
•    High Rigidity in bending and torsion.
•    Material Savings up to 25% compared to solid metal structures.
•    Easy Installation and connection.
•    Aesthetic Appearance.
•    Versatile Application.
•    Resistance to deformations.

Disadvantages
•    Limited Corrosion Resistance (without protective coating).
•    Difficulty in Manufacturing thick-walled pipes of large cross-sections.
•    Stresses in the corner zones of the profile.

Areas of Application
•    Construction: building frames, columns, trusses, supports.
•    Mechanical Engineering: frames, structures, mechanism components.
•    Furniture Manufacturing: furniture frames, shelving.
•    Automotive Industry: body elements, frames.
•    Advertising Structures: billboards, steles, frames.
•    Agriculture: greenhouses, livestock complex structures.

Normative Documentation (GOST Standards)
Main standards regulating the production of square profile pipes:
GOST 8639-82 – "Steel square pipes. Assortment"
•    Establishes the complete list of cross-section sizes.
•    Defines wall thicknesses for each size.
•    Regulates limit deviations for geometry.
•    Indicates the theoretical mass of 1 meter of pipe.
GOST 13663-86 – "Steel profile pipes. General technical specifications"
•    Defines steel grades and mechanical properties.
•    Establishes test methods and quality control.
•    Regulates acceptance and marking rules.
Additional Standards:
•    GOST 10705-80 – Requirements for welded seams.
•    GOST 5632-2014 – For stainless steels.
•    GOST 19281-2014 – For pipes made of high-strength steel.
Classification by Production Method:
•    Cold-deformed (cold-bent)
•    Hot-deformed (hot-bent)
•    Electric-welded
•    Seamless