Topic: High gloss black finish...what grade aluminium?


Im currently looking for a way to improve my black anodised parts. At the moment we are using AL 5083 for our sheet metal parts and the results are quite inconsistent. We have a very high rejection rate and we want to improve this. Is it possible or likely that it is down to the type of aluminium we are using? The parts have to be high gloss black and be perfect as they will be very visible. At the moment some parts are coming back from the anodisers dull .

From research i have found that 5083 might not be the best to use. What would be  more suitable? From looking online some people are saying 6463,6060 or 5005 might be better but are these available in sheet? Would changing alloy bve a likely remedy to the problem?

Thanks guys



Re: High gloss black finish...what grade aluminium?

The alloy of the aluminum does play a big part in how it can be finished successfully. The alloy is usually chosen with other parameters in mind too, like machinability, corrosion resistance, strength, etc.  If you are open to changing your alloy, then by all means try out some different stuff.  However, if you are getting some good parts with the current alloy, it is more likely that the anodizer does not have good control over his process, which is resulting in the creation of bad parts. 

When looking at a different alloy, avoid silicon, magnesium, and copper.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer


Sanford, NC