Aluminium extrusion

Selecting the correct alloy is critical for performance. For general structural use, 6063 is the standard for architectural applications due to its excellent finish and corrosion resistance. For high-strength requirements, 6061 is preferred for structural components like bridges and heavy machinery. If the product is for the automotive or aerospace sector, ensure the supplier can provide 7075 series for high stress-to-weight ratios.

Buyers must confirm adherence to ASTM B221 or EN 755/12020 standards for dimensional accuracy. It is essential to specify wall thickness tolerances (typically ±0.1mm to ±0.5mm) and surface finish requirements, such as Anodizing (10-25 microns), Powder Coating (60-80 microns), or Electrophoresis, to ensure durability and aesthetic consistency.

Request a Material Mill Test Certificate (MTC) to verify chemical composition and mechanical properties like Tensile Strength, Yield Strength, and Elongation. For complex hollow profiles, ensure the supplier uses high-quality extrusion dies to prevent 'weld lines' or structural weaknesses. Conduct a Hardness Test (Webster or Brinell) on samples to confirm proper heat treatment (T5 or T6 temper).

Custom profiles require a one-time tooling fee (Die Charge). Ensure the supplier provides a CAD/DWG drawing for approval before die casting. Professional suppliers on Made-in-China.com often offer die fee refunds once the cumulative order volume reaches a specific threshold (e.g., 5-10 tons). Always request a first-article inspection (FAI) sample from the new mold before proceeding with bulk extrusion.

Aluminium prices are tied to the London Metal Exchange (LME). To manage volatility, negotiate a pricing formula (LME Base Price + Processing Fee) rather than a fixed price. For large-scale projects, consider locking in the raw material price with a deposit when the market rate is favorable.

Aluminium is prone to surface scratches and bending during transit. Insist on EP foam wrapping for each profile, followed by shrink film bundling and wooden crate or pallet packaging for LCL shipments. Ensure the container is dry to prevent white rust (oxidation) caused by moisture during sea freight.

Many countries (e.g., USA, EU, Australia) impose Anti-Dumping and Countervailing Duties on Chinese aluminium extrusions. Before ordering, check your local HS Code (typically 7604.21 or 7604.29) regulations. Work with experienced exporters on Made-in-China.com who can provide Certificate of Origin or suggest 'Third-Country Transshipment' if legally viable for your region.

Utilize Secured Trading Services provided by platforms like Made-in-China.com to protect your payment until the goods are shipped. Always conduct a Pre-shipment Inspection (PSI) via a third party like SGS or Intertek to verify quantity, length, and finish quality before the final balance payment is released.