1. Product Definition & Classification
Aluminum square tubes are hollow structural profiles with four equal sides, formed through extrusion processes. They are classified by:

• Alloy Type:
  • 6000 Series (e.g., 6061-T6): High strength, excellent weldability, and good corrosion resistance; ideal for structural applications.
  • 6000 Series (e.g., 6063-T5): Superior surface finish and formability; commonly used in architectural and decorative contexts.
  • Other Alloys (e.g., 2024, 7075): For specialized high-stress or aerospace needs, offering enhanced mechanical properties.
• Temper Designation: Indicates heat treatment (e.g., T6 for solution heat-treated and artificially aged, T5 for artificially aged only), affecting hardness and ductility.

2. Key Specifications

• Dimensions:
  • Outer Width (Sides): Ranges from 10mm (0.4 inches) to 200mm (8 inches); common sizes include 25mm, 50mm, and 100mm.
  • Wall Thickness: Typically 1.0mm to 12.7mm (0.04–0.5 inches); standard options are 1.5mm, 3.0mm, and 6.0mm.
  • Length: Standard lengths of 6,000mm (20 feet) or 12,000mm (40 feet); custom cuts available.
• Tolerances: Governed by standards like ASTM B221 or EN 755-9 for straightness, twist, and dimensional accuracy (±0.5mm on width).
• Surface Finish: Options include:
  • Mill finish (as-extruded), anodized (for enhanced corrosion resistance and color), powder-coated (for aesthetics and durability), or brushed/polished.

3. Material Properties
Critical properties for performance evaluation:

• Density: Approximately 2.7 g/cm³, making it 1/3 the weight of steel for equivalent volume.
• Tensile Strength: Varies by alloy—e.g., 6061-T6: 310 MPa min, 6063-T5: 170 MPa min.
• Yield Strength: E.g., 6061-T6: 275 MPa min, ensuring load-bearing capacity without deformation.
• Corrosion Resistance: Natural oxide layer provides excellent resistance to weathering, chemicals, and salt; enhanced by anodizing.
• Thermal and Electrical Conductivity: High thermal conductivity (~200 W/m·K) and electrical conductivity (~35% IACS), suitable for heat sinks and electrical enclosures.
• Weldability and Machinability: Easily welded (TIG/MIG) and machined; low melting point requires care to avoid distortion.

4. Manufacturing Process Overview

1. Billet Preparation: Aluminum ingots are homogenized and cut into billets.
2. Extrusion: Billets heated to 400–500°C and forced through a square-shaped die using hydraulic presses, forming continuous lengths.
3. Heat Treatment: Artificial aging (e.g., T5, T6) to achieve desired temper and mechanical properties.
4. Cutting and Finishing: Extrusions are cut to length, then surface-treated (e.g., anodizing, coating) for protection and appearance.
5. Quality Control: Non-destructive testing (e.g., ultrasonic for wall consistency) and dimensional checks per standards.

5. Primary Applications

• Construction and Architecture: Framing for windows, doors, curtain walls, and structural supports in buildings; favored for light weight and corrosion resistance.
• Automotive and Transportation: Chassis components, roll cages, and trailer frames due to high strength-to-weight ratio.
• Furniture and Fixtures: Shelving, tables, and display units; easy to fabricate and aesthetically versatile.
• Industrial Machinery: Conveyor systems, guards, and frames in manufacturing plants.
• Renewable Energy: Solar panel mounting structures and wind turbine components.
• Consumer Goods: Bicycle frames, sports equipment, and DIY projects.

6. Selection Guidelines
Choose based on:

• Load Requirements: Higher strength alloys (e.g., 6061) for heavy loads; thinner walls for light-duty applications.
• Environmental Exposure: Anodized or coated finishes for corrosive or outdoor settings.
• Fabrication Needs: Alloys with good weldability (e.g., 6061) for complex assemblies; consider machinability for precision parts.
• Cost-Effectiveness: 6063 for cost-sensitive, non-structural uses; 6061 for balanced performance.
• Regulatory Compliance: Adhere to standards like ASTM B221 (US), EN 755 (EU), or JIS H4100 (Japan) for safety and quality.

7. Quality Standards and Assurance

• International Standards:
  • ASTM B221: Standard specification for extruded bars, rods, and profiles.
  • EN 755-9: European norm for extruded profiles, including dimensional tolerances.
  • ISO 6361: For wrought aluminum and aluminum alloy sheets, strips, and plates.
• Certification: Mill Test Certificates (MTCs) provided, detailing chemical composition, mechanical tests, and heat treatment. Third-party inspections (e.g., SGS, TÜV) available.

8. Advantages

• Light Weight: Reduces transportation and installation costs; ideal for weight-sensitive designs.
• Corrosion Resistance: Long service life with minimal maintenance, even in harsh environments.
• Recyclability: 100% recyclable with low energy input, supporting sustainability goals.
• Ease of Fabrication: Simple to cut, drill, weld, and bend, enabling custom designs.
• Aesthetic Flexibility: Various finishes allow for decorative and functional integration.
• Cost-Efficiency: Lower lifecycle costs compared to alternatives like steel.

9. Packaging and Handling

• Tubes are bundled with protective caps on ends and wrapped in VCI (Vapor Corrosion Inhibitor) paper or plastic to prevent damage and corrosion.
• Stacked on pallets and secured with steel strapping; handle with care using non-marring tools to avoid surface scratches. Store in dry, covered areas to maintain integrity.

10. Ordering Information
Specify clearly:

• Alloy and Temper (e.g., 6061-T6)
• Dimensions (Outer Width x Wall Thickness x Length, e.g., 50mm x 3.0mm x 6000mm)
• Quantity (Number of pieces or total weight in kg/lbs)
• Surface Finish (e.g., Mill finish, Anodized Clear, Powder Coated RAL color)
• Cutting Requirements (e.g., Full lengths, custom cuts with tolerances)
• Certification Needs (e.g., EN 10204 3.1 MTC, Third-Party Inspection Report)
  For quotes or technical support, provide project details to our engineering team.