Square & Rectangular Hollow Sections

Product Overview

As core structural products of Baolai Steel Group, Baolai Square & Rectangular Hollow Sections (SHS/RHS) offer comprehensive square and rectangular profile solutions to meet the diverse needs of global industries including construction, infrastructure, machinery manufacturing and renewable energy. With a full range of size specifications, multiple material grades and flexible corrosion protection options, these hollow sections combine high structural performance, dimensional precision and reliable quality, making them a trusted choice for large-scale engineering projects and industrial applications worldwide.

Size Specifications

Baolai provides a complete size range to accommodate different load requirements and application scenarios, with multiple wall thickness and surface finish options:

· Square (SHS): Available in sizes from 12×12mm to 150×150mm, with wall thickness ranging from 0.4mm to 2.5mm. Surface finishes include painted or pre-galvanized, suitable for lightweight structural applications with moderate load demands.

· Rectangular (RHS) – Regular: Offers two size series, including 20×20mm to 1100×1100mm and 20×30mm to 1100×1000mm, with wall thickness from 1.3mm to 60mm. Surface finishes include painted or hot-dip galvanized, designed for heavy-duty structural projects requiring high load-bearing capacity.

· RHS – Light-gauge: Covers sizes from 8×16mm to 50×100mm, with wall thickness between 0.4mm and 2.5mm, available in painted or pre-galvanized finishes, ideal for lightweight frameworks and non-load-bearing structural components.

Standard lengths are 6m and 12m, with custom lengths available to meet specific project requirements. End processing options include plain, beveled (30°), grooved or threaded, facilitating easy connection and installation on site.

Standards & Material Grades

Baolai Square & Rectangular Hollow Sections comply with international and domestic industry standards, ensuring compatibility with global project specifications and quality requirements:

· EN 10219 (cold-formed): Available in grades S235JRH, S275JOH, S275J2H, S355JOH, S355J2H, suitable for cold-formed structural components with excellent weldability and formability.

· EN 10210 (hot-finished): Uses the same grades as EN 10219, featuring higher strength and better mechanical properties, ideal for heavy-load structural applications.

· ASTM A500: Offers grades A, B, C, D, with Grade B being the most commonly used, meeting the requirements of North American structural engineering projects.

· Additional grades: Q235, Q355, ASTM A36, SS400, S275JR, S355JR are also available, providing flexible material options for different regional standards and project needs.

Manufacturing Process & Quality Control

Baolai adopts advanced automated production lines to ensure consistent product quality and dimensional accuracy. The complete manufacturing process includes uncoiling, leveling, cold-forming, high-frequency welding, cooling, sizing, online non-destructive testing (NDT), cutting and straightening. Each step is strictly controlled to guarantee the precision of dimensions, straightness, twist tolerance and weld quality of the hollow sections.

With 13 professional production lines, Baolai has an annual production capacity of over 5 million tons, and maintains standing stock of more than 200,000 tons, enabling fast delivery to meet urgent project timelines. The online NDT process ensures that every product meets quality standards, eliminating defects and ensuring the reliability of structural components.

Core Performance Features

Baolai Square & Rectangular Hollow Sections are designed to deliver superior structural performance, making them stand out from traditional open-profile steel products:

· High strength-to-weight ratio: The closed-section design distributes stress evenly across the entire profile, providing higher load-bearing capacity than open-profile steel products of the same weight. This reduces overall project weight and material costs while maintaining structural integrity.

· Superior torsional resistance: The closed rectangular and square shapes offer excellent torsional stiffness, making them ideal for structural components that need to withstand twisting forces, such as crane booms, bridge bracings and machinery frames.

· Easy joint connection: The flat, smooth ends of the hollow sections simplify welding, bolting and other connection methods, reducing on-site installation time and labor costs, while ensuring stable and reliable joint performance.

· Clean aesthetic appearance: The smooth, uniform surface of the hollow sections provides a clean and modern aesthetic, eliminating the need for additional finishing in visible structural applications such as building facades, stadium roofs and public facilities.

· Flexible corrosion protection: Multiple surface finish options including paint, pre-galvanized and hot-dip galvanized are available to suit different environmental conditions. Hot-dip galvanizing provides long-term corrosion resistance for outdoor and offshore applications, while painted finishes offer customizable color options for aesthetic requirements.

Application Scenarios

Baolai Square & Rectangular Hollow Sections are widely used in various industries, providing reliable structural solutions for diverse project types:

1. Building structures: Used as columns, beams, trusses and bracings in commercial buildings, residential buildings and industrial workshops, providing stable support for multi-story and large-span structures.

2. Bridges & transportation: Applied in footbridges, guardrails, station frames and highway infrastructure, offering excellent torsional resistance and corrosion resistance to withstand harsh outdoor environments.

3. Long-span venues: Utilized in stadium roofs, exhibition halls and airport terminals, leveraging the high strength-to-weight ratio to create lightweight yet durable large-span structures.

4. Offshore engineering: Used in platform modules, trestles and fenders, with hot-dip galvanized finish providing superior corrosion resistance to withstand saltwater and humid offshore conditions.

5. Machinery: Applied in crane booms, equipment frames, conveyors and agricultural chassis, offering high torsional stiffness and load-bearing capacity to support heavy machinery operations.

6. Renewable energy: Used in PV mounts and wind tower internals, providing stable structural support for solar and wind energy systems, with corrosion-resistant finishes ensuring long-term performance in outdoor environments.

7. Warehousing: Utilized in rack uprights, beams and guide rails, offering high vertical load-bearing capacity to support heavy storage systems in warehouses and distribution centers.

8. Municipal works: Applied in lamp poles, traffic poles, billboards and fencing, combining aesthetic appearance with durable performance to meet urban infrastructure needs.

Target Customer Groups

Baolai Square & Rectangular Hollow Sections serve a wide range of global customers, including construction companies, infrastructure engineering firms, machinery manufacturers, renewable energy project developers, warehousing facility builders, municipal engineering contractors, steel product distributors and export trading companies. Whether for large-scale engineering projects or small-scale structural applications, Baolai provides tailored solutions to meet specific customer needs.

Common Questions FAQ

Q1: What is the difference between cold-formed and hot-finished hollow sections?
A: Cold-formed hollow sections are produced by cold-forming steel coils, offering excellent formability and weldability, suitable for lightweight structural components. Hot-finished hollow sections are manufactured through hot rolling and forming, providing higher strength and better mechanical properties, ideal for heavy-load applications.

Q2: Can I get custom lengths for Baolai hollow sections?
A: Yes, besides standard lengths of 6m and 12m, custom lengths are available to meet specific project requirements, ensuring optimal material utilization and reducing on-site cutting work.

Q3: Which surface finish is suitable for offshore applications?
A: Hot-dip galvanized finish is recommended for offshore engineering, as it provides superior corrosion resistance to withstand saltwater, humidity and other harsh environmental conditions, extending the service life of the structural components.

Q4: What standards do Baolai hollow sections comply with?
A: Baolai hollow sections comply with international standards including EN 10219, EN 10210 and ASTM A500, as well as domestic standards with grades such as Q235 and Q355, ensuring compatibility with global project specifications.

Q5: How does Baolai ensure product quality?
A: Baolai adopts automated production lines and strict quality control processes, including online non-destructive testing (NDT) at each production stage. With 13 professional lines, annual capacity of over 5 million tons and standing stock of more than 200,000 tons, Baolai ensures consistent product quality and fast delivery.