Q235 Black Powder Coated Square Tubing is a high-quality structural steel product, widely used in construction, manufacturing, and structural applications. Its powder-coated surface provides corrosion resistance and an attractive finish, suitable for both industrial and decorative purposes.
Specifications
| Parameter | Details |
|---|---|
| Product Name | Hot Sale Black Iron Square Tube / Black Chinese Tube |
| Steel Grade | Q235 (Grade A) |
| Type | Round / Square / Rectangular Tubing |
| Alloy | Non-Alloy |
| Outer Diameter | 10×10 mm – 600×600 mm |
| Wall Thickness | 0.6 – 25 mm |
| Length | 5.8 – 12 m (customizable) |
| Surface Treatment | Black powder coated, oiled |
| Application | Construction structures, general metal fabrication |
| MOQ | 20 GP container |
| Keyword | Mill Test Certificate Steel Pipe |
| Port | Qingdao, Tianjin |
| Package | Standard export packing in bundles |
Applications
1. Structural Steel for Buildings and Bridges
Q235 square and rectangular tubing is widely used as beams, columns, and support frameworks in residential, commercial, and industrial buildings.
Tensile strength of 370–500 MPa and yield strength of ≥235 MPa ensure it can safely bear static and dynamic loads.
High elongation (20–26%) allows the steel to deform slightly under extreme loads without fracturing, making it suitable for earthquake-prone regions.
Example: Used in structural frameworks of warehouses, multi-story buildings, and small to medium-span bridges where low-carbon, ductile steel is preferred.
2. General Metal Manufacturing and Fabrication
Ideal for fabrication of machine frames, supports, brackets, and structural panels due to good weldability and machinability.
Low carbon content (0.12–0.20%) minimizes welding defects such as cracking and distortion, improving production efficiency.
Can be easily cut, bent, or formed to precise tolerances (±1–3%), supporting custom industrial fabrication.
Example: Vehicle chassis components, conveyor systems, and industrial racks.
3. Decorative and Architectural Applications
Black powder coating or oiled surface provides corrosion resistance and a visually appealing finish for exposed structures.
Can be used in handrails, gates, fences, pergolas, furniture frames, and façade panels.
Coating thickness of 30–80 μm (typical powder coat) ensures long-term durability with minimal maintenance.
Example: Modern building facades, outdoor furniture, or artistic metal structures requiring both structural strength and aesthetic quality.
4. Infrastructure and Utility Applications
Commonly used in power plant scaffolding, pipeline supports, and storage racks where medium-load carrying capacity is required.
Hot-dip galvanization or powder coating ensures resistance to corrosion in outdoor or industrial environments.
Can withstand environmental conditions such as humidity, light rain, and UV exposure without significant degradation.
5. Automotive and Mechanical Applications
Used in non-critical automotive components such as trailer frames, chassis supports, and machinery housings.
Strength-to-weight ratio is optimized for cost-effective manufacturing while maintaining durability.
