Q355 square steel tube

Square tubes are used in construction, machinery manufacturing, steel construction projects, shipbuilding, solar panel supports, steel structure engineering, electrical engineering, power plants, agricultural and chemical machinery, glass curtain walls, automotive underbodies, airports, boiler construction, highway guardrails, building construction, pressure vessels, oil storage tanks, bridges, power station equipment, lifting and transportation machinery, and other welded components with high loads.

Square Tube Categories

Process Category

Square tubes are classified 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 welding process – Arc Welded Square Tubes, Resistance Welded Square Tubes (High Frequency, Low Frequency), Gas Welded Square Tubes, Furnace Welded Square Tubes

(b) Seam Type - Straight Seam Square Pipe, Spiral Seam Square Pipe

Material Categories

Square tubes are categorized by material: Carbon Steel Square Tubes and Low-Alloy Steel 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 Standard Classification

Square tubes are classified according to production standards: GB square tubes, JIS square tubes, BS square tubes, ASME square tubes, DIN square tubes, and non-standard square tubes.

Section Shape Classification

Square tubes are classified according to their cross-sectional shapes:

Simple Square Tubing - Square Tubing, Rectangular Tubing

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