Welding Square And Rectangular Tubes
Product description:

Welded Square and rectangular tubes, also known as welded hollow sections (WHS), are essential structural materials widely used in construction, mechanical manufacturing, automotive engineering, furniture production, and industrial frameworks. These tubes are formed by rolling and welding steel strips or coils into square or rectangular shapes, offering excellent strength, dimensional precision, and cost efficiency. Compared with seamless tubes, welded tubes provide greater flexibility in size customization, lighter weight, and more economical production — making them a preferred choice for structural and decorative applications worldwide.

Square and rectangular sectioned steel pipes are collectively referred to as square and rectangular sectioned steel pipes, and they belong to a type of welded steel pipes. They are also known as "steel cold-formed sections".

Due to their unique cross-sectional shape and excellent mechanical properties, square and rectangular sectioned steel pipes are widely used in modern industries, construction and manufacturing, and have become an indispensable basic steel material.

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Manufacturing Process

The manufacturing of welded square and rectangular tubes involves several precise stages to ensure high quality and performance:

• Material Preparation: High-quality hot-rolled or cold-rolled steel coils (carbon steel, alloy steel, or stainless steel) are selected and inspected.
• Forming: The steel strip is passed through a series of rollers that gradually shape it into a round, square, or rectangular form.
• Welding: The edges of the formed tube are high-frequency welded (ERW) or submerged arc welded (SAW) to create a continuous, durable seam.
• Sizing and Straightening: The welded tube is shaped to the exact square or rectangular dimensions and straightened to maintain precision.
• Cutting and Finishing: Tubes are cut to specific lengths and may undergo surface treatments such as galvanizing, pickling, or painting.
• Quality Inspection: Every tube is tested for weld integrity, surface smoothness, and dimensional tolerance to meet international standards.

This process ensures that welded hollow sections have consistent wall thickness, tight tolerances, and smooth surfaces suitable for both load-bearing and decorative applications.

Material Grades

• Carbon Steel: S235JR, S275JR, S355JR, Q195, Q235, Q345
• Alloy Steel: 20MnV6, 30CrMo, 42CrMo
• Stainless Steel: 304, 316L, 321, 201
• Each grade offers specific advantages such as higher yield strength, corrosion resistance, or formability, allowing for optimal selection based on project requirements.

Advantages

• Cost-Effective: Lower production costs compared to seamless tubes without sacrificing strength.
• Wide Size Range: Easily customizable dimensions to meet different design needs.
• Smooth Surface Finish: Excellent for visible architectural and decorative structures.
• High Weld Quality: Modern ERW and SAW processes ensure consistent and durable seams.
• Good Machinability and Weldability: Suitable for bending, drilling, and fabrication.
• Lightweight Yet Strong: Excellent load-bearing capacity for frameworks and supports.

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Applications:

• Construction and Infrastructure: Building frames, scaffolding, bridges, and support columns.
• Mechanical Manufacturing: Machine frames, conveyors, and material handling systems.
• Automotive and Transport: Chassis, trailer frames, and structural reinforcements.
• Furniture and Interior Design: Modern furniture frames, handrails, and architectural accents.
• Agricultural and Energy Equipment: Machinery components, greenhouses, and solar panel mounts.
• Shipbuilding and Offshore: Light-duty marine structures and platforms.
• Their combination of formability, strength, and durability makes them suitable for both indoor and outdoor installations.

Quality Standards and Certifications

Welded square and rectangular tubes conform to international standards, ensuring reliability and global compatibility:

• EN 10219 – Cold-formed welded structural hollow sections
• EN 10210 – Hot-finished structural hollow sections
• ASTM A500 / A513 / A554 – Welded carbon and stainless steel tubes
• JIS G3466 – Structural steel square and rectangular tubes
• ISO 9001 / CE / SGS – Quality assurance and certification compliance

Company profile:

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Why us?

We focus on the research, development, production and sales of seamless steel pipes, Special-shaped steel pipes and hydraulic cylinders. We have a complete production chain and an advanced equipment system, including piercing machines, cold drawing machines, hot rolling machines, high-precision flaw detection and testing equipment. The company has passed multiple authoritative certifications such as ISO9001, API, SGS, CCS, DNV, ABS, CE, RoHS, etc., ensuring that each product complies with international standards. We are committed to providing customers with high-quality, customizable solutions to meet diverse application needs.

Relying on our own built processing base and modern workshops, combined with multiple branches and storage centers across the country, we have achieved sufficient inventory and efficient logistics coordination, significantly shortening the delivery cycle and ensuring the rapid delivery of orders.

We have established a complete service and support system. After the order is signed, the professional after-sales team can provide timely and safe on-site guidance and technical support to ensure that customers are at ease throughout the process from procurement to use.

FAQ:

1. Do you support customized design and production?

Sure. We have a professional engineering team that can conduct customized design and production with special sizes, control systems or OEM according to your requirements.

2. How fast can you deliver?

In stock sizes, it takes 3-5 days. For customized sizes, it takes 30-35 days.

3. What payment methods do you support?

We support TT payment. Generally, 30% to 50% of the payment is made in advance, and the remaining amount is paid before shipment.

4. Can you provide material certification (MTC)?

Yes, we will provide MTC to you after production is completed to ensure that the material quality meets the standards.

5. What is the minimum order quantity?

Generally, we accept trial orders. The minimum order quantity is 1-3 tons, which can be determined according to different products.