Rectangular steel tubes are used in construction, mechanical manufacturing, steel construction projects, shipbuilding, solar power generation supports, steel structure engineering, power engineering, power plants, agricultural and chemical machinery, glass curtain walls, automotive undercarriages, airports, boiler construction, highway guardrails, building construction, pressure vessels, oil storage tanks, bridges, power station equipment, lifting and transportation machinery, and other welding components with high load-bearing capacities.

Square Tube Categories

Process Classification

Square tubes are categorized by production process: hot-rolled seamless square tubes, cold drawn seamless square tubes, extruded seamless square tubes, and welded square tubes.

Among them, the welded square tubes are further divided into:

(a) By process – Arc Welded Square Tube, Resistance Welded Square Tube (High Frequency, Low Frequency), Gas Welded Square Tube, Furnace Welded Square Tube

(b) Weld Seam Type - Straight Seam Welded Square Tube, Spiral Seam Welded Square Tube

Material Categories

Square tubes are categorized by material: Carbon steel square tubes, low-alloy square tubes. Carbon steel includes: Q195, Q215, Q235, SS400, 20# steel, 45# steel, etc.; low-alloy steel includes Q345, 16Mn, Q390, ST52-3, etc.

Production Standards Classification

Square tubes are categorized by production standards: National Standard Square Tubes, Japanese Standard Square Tubes, British Standard Square Tubes, American Standard Square Tubes, European Standard Square Tubes, and Non-standard Square Tubes.

Section Shape Classification

Square tubes are classified by cross-sectional shape:

(1) Simple Square Pipe——Square Pipe, Rectangular Pipe

(2) Complex Section Square Tubes - Flower-shaped Square Tubes, Open-end Square Tubes, Wavy Square Tubes, Special-shaped Square Tubes