Description
Production process
The mainstream welding process for square tubes is high-frequency resistance welding (ERW), which involves continuous steel strip forming, fusion welding， internal and external deburring， straightening and alignment， and fixed-length cutting to produce the final product. Small-diameter thin-walled square tubes are produced at high speed with high precision； large-diameter thick-walled square tubes can be made using submerged arc welding， which results in deeper weld penetration and greater load-bearing capacity. The overall formation is free from splicing defects， and the welds are firm and stable， with low risk of cracking or deformation.
Common materials and standards
The conventional materials are Q235B and Q355B. These materials have stable properties， good weldability， and high toughness， making them less prone to brittle fracture. The products strictly follow the national standards GB/T 6725 and GB/T 6728. The dimensional tolerances, straightness, and cross-sectional flatness all meet the requirements for engineering acceptance. Regular material reports can be provided, and they can also meet the requirements of ASTM American standards for on-site customization.
Core advantages of the product
Compared to round tubes and other profiles, welded square tubes have well-defined corners, uniform stress distribution, excellent torsional, compressive, and bending performance, and a stronger overall structural stability; they have a square shape, good installation fit, and are easy to be welded, fixed with bolts, and assembled by splicing. The construction and formation are aesthetically pleasing. They can be freely cut, drilled, bent, and processed for beveling, suitable for various on-site customization conditions; they have strong mass production capabilities, complete specifications, and are economically priced, with a higher material yield rate than hot-rolled profiles, significantly reducing engineering costs. The finished products can undergo anti-corrosion treatments such as painting, rust removal, and hot-dip galvanizing according to requirements, extending the outdoor service life.
Specification range
The welded square tubes have a complete range of specifications, covering 15×15mm–400×400mm, with wall thicknesses ranging from 1.0mm to 16mm. The standard lengths are 6m, 9m, and 12m. Non-standard sizes and special fixed lengths can be customized, meeting different working conditions such as lightweight decoration, medium-sized structures, and heavy-duty load-bearing.
Main application scenarios
They are widely used in building steel structure frames, factory building columns, curtain wall keels, steel structure supports, municipal guardrails, road projects, mechanical equipment bases, steel frame shelves, stage trusses, temporary supports, and infrastructure projects, and are highly versatile core profiles in industrial and civil steel structure projects.
