Aluminum extrusion

Selecting the correct alloy is critical for performance. For general structural use, 6063 is preferred for its excellent surface finish and extrudability, making it ideal for windows and doors. For high-strength structural applications, 6061-T6 is the industry standard due to its superior mechanical properties and weldability. If your project involves marine environments, ensure the supplier provides 5000 or 6000 series alloys with high corrosion resistance.

Precision is paramount in extrusion. You must confirm adherence to ASTM B221 or EN 755 standards for dimensional tolerances. Request a die trial report and a cross-sectional drawing (CAD/DWG) for approval. Ensure the wall thickness tolerance meets your assembly requirements, and verify the temper designation (e.g., T5 or T6) to guarantee the required hardness and tensile strength.

Surface treatments enhance durability and aesthetics. Common options include Anodizing (minimum 10-15 microns for outdoor use), Powder Coating (Qualicoat certified), and Electrophoresis. For international compliance, ensure all coatings are RoHS and REACH compliant, meaning they are free from hazardous substances like lead or hexavalent chromium.

The quality of the final product depends on the die. Inquire if the supplier uses H13 steel for dies and performs nitriding treatments to extend die life and ensure surface smoothness. If you require post-processing, look for suppliers offering one-stop CNC fabrication, including precision cutting, drilling, tapping, and milling, to reduce logistics costs and assembly errors.

The primary risks include material substitution (using scrap aluminum instead of primary ingots) and dimensional deviations. To mitigate these, always request a Material Mill Test Certificate (MTC) and hire a third-party inspector like SGS or Intertek to perform a Pre-Shipment Inspection (PSI) focusing on weight verification and tolerance checks.

Aluminum pricing is usually calculated as: LME (London Metal Exchange) Aluminum Price + Fabrication/Processing Fee. To secure fair pricing, negotiate a formula-based pricing model rather than a fixed price, and clarify which day's LME rate will be used for the final invoice. For large orders, aim for a 10-15% discount on the fabrication fee.

Aluminum profiles are easily scratched or bent. Insist on interleaving with EPE foam or paper between each profile. For sea freight, use strong wooden crates or steel pallets rather than just plastic wrapping. Ensure the supplier uses desiccants inside the containers to prevent 'white rust' (oxidation) caused by humidity during transit.

Many countries (including the US and EU) impose Anti-Dumping (AD) and Countervailing Duties (CVD) on aluminum extrusions from specific regions. Before ordering, check your local customs tariff schedule using the HS Code (typically 7604.21 or 7604.29). To ensure a smooth transaction, source from reputable manufacturers on Made-in-China.com who are experienced in providing the necessary Certificate of Origin and trade documentation.