Aluminum Alloys & Anodizing

The right Aluminum Alloy for the right Anodizing Finish

We offer this Aluminum Alloy Reference to help SAF customers match specific alloys choices with anodizing finishing advice. Source: Aluminum Anodizers Council (AAC) Technical Bulletin #2-94, Aluminum Alloy Reference for Anodizing, issued March, 1994.

Aluminum Alloy Series (AA)* Alloying Constituents Metal Properties Anodized Coating Properties Uses A.Q.** Types Non-A.Q.** Types Aluminum Alloy Finishing Advice
1XXX none soft, conductive clear, bright cans, architectural none 1100, 1175 Care should be taken when racking this soft material good for bright coatings susceptible to etch, staining
2XXX Copper very strong, hard, low elongation yellow, poor protection aircraft, mechanical none 2011, 2017, 2219, 2224 Since copper content is >2%, these produce yellow, poor weather-resistant coatings. Don’t mix with other alloys on load
3XXX Manganese strong, small grain grayish-brown cans, architectural, lighting none 3003, 3004 Difficult to match sheet-to-sheet (varying degrees of gray / brown). Used extensively for architectural painted products
4XXX Silicon strong, fluid dark gray architectural, lighting none 4043, 4343 Produces heavy black smut which is hard to remove 4043 & 4343 used for architectural dark gray finishes in past years
5XXX Magnesium strong, ductile, fluid clear, good protection architectural, welding wire, lighting 5005, 5657 5052, 5252 for 5005 – keep silicon <0.1% and magnesium between 0.7% and 0.9%, maximum of +/- 20% for job watch for oxide streaks
6XXX Magnesium & Silicon strong, ductile clear, good protection architectural, structural 6063, 6463 6061, 6101 Matte – iron >0.2%, bright – iron <0.1%, 6063 best match for 5005, 6463 best for chemical brightening
7XXX Zinc very strong clear, good protection automotive none 7029, 7046, 7075 Zinc over 5% will produce brown, tinted coatings, watch zinc in effluent stream, good for bright coatings

This information used by permission of the AAC