Square & Rectangular Steel Tubes – Ideal Profiles for Structural Support & Precision Manufacturing
We offer a full range of square and rectangular steel tubes. Our products are widely used in steel structure engineering, machinery manufacturing, photovoltaic brackets, automotive chassis, curtain wall decoration, bridge construction, and shipbuilding. We manufacture strictly according to international standards and support customized sizes, galvanized corrosion protection, and further processing services.
- Product Range, Sections & Standards
1) Square and Rectangular Tube Product Classification
Square and rectangular tubes are classified into square tubes and rectangular tubes according to their cross-sectional shape. Manufacturing processes include high-frequency straight seam welded pipe (ERW), cold bending forming, and hot rolling seamless processes.
2) Standards: We support major global industry standards to ensure our products meet the access requirements of different markets:
GB: GB/T 6725, GB/T 6728 (Cold-formed hollow steel sections)
ASTM: ASTM A500 (Cold-formed welded pipe), ASTM A501 (Hot-formed carbon steel structural pipe)
EN: EN 10219 (Cold-formed welded hollow profiles), S235JR, S275JR, S355JRH, S355J2H
JIS: JIS G3466 (Carbon steel pipes for general structural use)
International Standards: ISO, API 5L (Pipeline specifications)
3) Grades: We offer a variety of material options to suit different applications:
Carbon Steel Series:
GB: Q195, Q215, Q235B/C/D, Q345B, Q355B
ASTM: ASTM A36, A53 Gr.B, A500 Gr.B/C, A501 Grade A/B/C
European Standard: S235JR, S275JR, S355JR, S355J2H
Japanese Standard: SS330, SS440, SS490, STKR400, STKR490
- ·· Stainless Steel Series:
300 Series: 304, 304L, 316, 316L, 310S
200 Series: 201, 202 (Price-sensitive applications)
High Strength Steel Series: Q390, Q420, Q460, S460, S420
- Size Range Overview: Square and rectangular tubes cover a complete range of specifications, from micro-precision tubes to ultra-large diameter thick-walled tubes, meeting the diverse needs of various industries.
| parameter | Range(mm) | Customization capabilities |
| Square tube (HSS tube)Width | 10x10mm-1000x1000mm | Supports non-standard size customization |
| Rectangular tube Width | 20×10mm – 800×1200mm | Supports customization of any aspect ratio |
| Thickness | 0.5-60mm | Customization available according to load-bearing requirements |
| Length m | 1-12m | Fixed-length cutting accuracy ±2mm |
| Special Specifications | Maximum size can reach 1200×1200×50mm | Suitable for super-large buildings |
- Key Differentiators
1) Large Diameter and Thick-Wall Production Capacity
We possess internationally leading square and rectangular tube production lines, capable of producing the world’s largest diameter single-weld square and rectangular tubes (1200×1200×50mm), providing high-quality material support for ultra-large and ultra-high-rise buildings. Our products are widely used in landmark projects both domestically and internationally, such as Beijing Daxing International Airport, Qatar World Cup venues, Dubai Expo, and the Hong Kong-Zhuhai-Macau Bridge.
2) High Dimensional Accuracy and Clear Right Angles
Utilizing high-precision cold bending and sizing technology, we ensure clear 90-degree right angles, small diagonal tolerances, and a smooth surface for our square tubes. For precision manufacturing, our products meet stringent dimensional tolerance requirements, reducing subsequent processing and adjustment costs for our customers.
3) Diverse Material Options for Complex Working Conditions
Customized material solutions are provided based on application scenarios:
Building Structure: Q355B/S355JR, meeting seismic performance requirements
Photovoltaic Support: Q235B/S235JR, cost-effective, hot-dip galvanized optional
Automotive Chassis: High-strength steel series, weight reduction while maintaining strength
Marine Environment: 316L stainless steel or zinc-aluminum-magnesium coated square tubing, excellent corrosion resistance
Low Temperature Environment: ASTM A333 Gr.6, suitable for extremely cold regions
✔ Galvanized Corrosion Protection Capabilities
- Offers multiple galvanized corrosion protection solutions to suit different usage environments:
- Blow plating: Average zinc layer 30μm (426g on both sides), suitable for general corrosion protection scenarios.
- Rack plating: Average zinc layer 60μm, up to 100μm, excellent corrosion protection performance, suitable for harsh environments.
- Zinc-aluminum-magnesium coating: Higher corrosion resistance, self-healing cuts.
- 3PE coating/epoxy powder coating: Suitable for high corrosion protection requirements such as buried pipelines.
✔ Strong Inventory and Spot Stock Capabilities
Standard length inventory: Covering various products including black pipes, hot-dip galvanized pipes, zinc-aluminum-magnesium pipes, etc., with nearly 9,000 specifications, meeting the needs of large-scale procurement and urgent orders. Regular specifications are shipped within 48 hours, and specially customized products are delivered in 7-30 days.
- Quality Assurance
We have established a complete quality control system from raw materials to finished product delivery to ensure that every square and rectangular tube meets international standards. 1) Four-fold Inspection System
Raw Material Inspection: X-ray fluorescence spectrometry is used to conduct 100% testing of the chemical composition of steel coils to ensure compositional stability.
Dimensional Accuracy Inspection: Strict dimensional, weight, and thickness measurements are implemented at each stage of the production process to ensure compliance with standards.
Forming Inspection: Roundness (round tubes), edge angles (rectangular tubes), and straightness are inspected for square tubes.
Weld Strength Inspection: Eddy current testing, flaring test, flattening test, and leveling test are conducted according to ASTM/JIS/BS EN standards.
Zinc Coating Quality Assurance
Uniformity Test: No red metallic copper deposition was observed after five consecutive copper sulfate immersion tests, confirming no missed plating.
Adhesion Verification: After a cold bending test (bending angle 90°, bending radius 8 times the pipe diameter), the coating showed no peeling or cracking.
Zinc Coating Thickness: Strictly in accordance with GB/T 6728-2017 and group standard T/CSCS TC02-04-2018, the zinc coating thickness and uniformity are superior to national standards.
2) International Certification:
ISO 9001:2015 Quality Management System
CE Certification (EN 10219, EN 10210)
ASTM Certification (Complies with ASTM A500/A501 standards)
BV/SGS Third-Party Inspection Agency Accreditation
EN 10204 3.1/3.2 Material Certificate Available
3) Digital Traceability System
Each batch of products is traceable to the raw material furnace number, production batch, and quality inspection records, ensuring that quality issues are traceable and manageable.
- After-Sales & Technical Support
1) 100% After-Sales Quality Guarantee: We promise a 100% after-sales guarantee for product quality and quantity.
2) Professional Technical Support:
Material Selection Consultation: A professional engineering team can assist customers in selecting materials based on load-bearing requirements, usage environment, and industry standards.
3) Processing Suggestions: We provide suggestions on processing techniques such as cutting, drilling, bending, and welding to ensure processing quality.
4) Construction Guidance: We can provide on-site installation guidance services to ensure smooth project progress.
5) Own Fleet Transportation: We track and inspect goods throughout the entire process to ensure accurate delivery to the designated port.
Seamless Logistics: From the factory to the processing plant, from the annealing plant to the galvanizing plant and then to the project site, we achieve full logistics coordination.
- OEM Customization Services
1) Size Customization
Fixed-Length Cutting: We can cut any length according to customer requirements with an accuracy of ±2mm.
Non-standard Specifications: We support customization of special side lengths, wall thicknesses, and aspect ratios.
Minimum Order Quantity: We support small orders (starting from 1 ton) to meet the needs of trial orders and small projects.
2) Customized Materials
Matching exclusive materials according to different industry needs:
Building Structure: Q235B/Q355B, galvanized as needed
High-Strength Applications: Q390-Q460 high-strength steel
Corrosion-Resistant Environments: 316L stainless steel or zinc-aluminum-magnesium plating
3) Value-Added Processing
Cutting/Drilling: Precision cutting, supports irregular hole processing to meet pipe connection needs
Bending/Welding: Equipped with cold bending units to achieve complex bending shapes; provides professional welding services to ensure structural strength
Customized Galvanizing: Adjusting galvanizing thickness according to the usage environment to balance cost and corrosion resistance
Surface Treatment: Painting, sandblasting, sandblasting and oiling, 3PE anti-corrosion, polyurethane insulation layer
4) Customized Packaging and Labeling
Export Packaging: Securely bundled, wrapped in waterproof cloth or palletized, suitable for sea freight
Pipe End Protection: Plastic pipe caps seal both ends of the steel pipe to prevent transportation damage
Customized Markings: Labels affixed according to customer requirements (project name, furnace batch number, component number, QR code, etc.)
5) OEM/ODM Services
OEM Branding: Customization of product labels, packaging, and warranty certificates according to customer requirements.
ODM Development: Development of products with special specifications or performance characteristics based on customer needs.
- Why Choose Us?
Size Limits: Maximum production capacity of extra-large diameter square and rectangular tubes up to 1200×1200×50mm.
Standard Coverage: Multiple standard certifications including GB, ASTM, EN, JIS, and API.
Deep Processing Capabilities: One-stop service for cutting, drilling, bending, welding, and galvanizing.
Delivery Capabilities: Standard sizes shipped within 48 hours; custom orders within 7-30 days.
Free Samples: High-quality 20cm free samples available.
