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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 ConstituentsMetal PropertiesAnodized Coating PropertiesUsesA.Q.** TypesNon-A.Q.** TypesAluminum Alloy Finishing Advice
1XXXnonesoft, conductiveclear, brightcans, architecturalnone1100, 1175Care should be taken when racking this soft material good for bright coatings susceptible to etch, staining
2XXXCoppervery strong, hard, low elongationyellow, poor protectionaircraft, mechanicalnone2011, 2017, 2219, 2224Since copper content is >2%, these produce yellow, poor weather-resistant coatings. Don’t mix with other alloys on load
3XXXManganesestrong, small graingrayish-browncans, architectural, lightingnone3003, 3004Difficult to match sheet-to-sheet (varying degrees of gray / brown). Used extensively for architectural painted products
4XXXSiliconstrong, fluiddark grayarchitectural, lightingnone4043, 4343Produces heavy black smut which is hard to remove 4043 & 4343 used for architectural dark gray finishes in past years
5XXXMagnesiumstrong, ductile, fluidclear, good protectionarchitectural, welding wire, lighting5005, 56575052, 5252for 5005 – keep silicon <0.1% and magnesium between 0.7% and 0.9%, maximum of +/- 20% for job watch for oxide streaks
6XXXMagnesium & Siliconstrong, ductileclear, good protectionarchitectural, structural6063, 64636061, 6101Matte – iron >0.2%, bright – iron <0.1%, 6063 best match for 5005, 6463 best for chemical brightening
7XXXZincvery strongclear, good protectionautomotivenone7029, 7046, 7075Zinc over 5% will produce brown, tinted coatings, watch zinc in effluent stream, good for bright coatings

This information used by permission of the AAC