For our aluminum products we use as a minimum 5005 (AlMg1) quality which is specifically designed for outdoor applications without any coating. This means less risk of filiform corrosion. For products that need to be anodized, we use, inter alia, J57S-quality order to minimise the risk of colour deviation.
With regards to powder coating or anodizing, we only use suppliers who are Qualicoat or Qualanod certified.
We always use 6060 quality for extruded profiles.