Determining aluminum alloy type

[bdrmachine]

Is there an easy way to determine the alloy type of scrap (unmarked) aluminum plate. I need to machine a plate (6061) that will be anodized. All of the local anodizing shops in town refuse to work with 2024 due to the extra step needed to remove the copper.

Thanks
Brian

[fifesmith]

No easy way that I know of. We send out samples of aluminum to a lab for analysis as part of the requirements for the FAA. This keeps our vendors honest (in theory.) It runs about $35 a sample.

[2muchstuff]

There is a tool that will determine alloy types. It generates an electric arc to burn away some of the aluminum and then reads the gas. I don't know who makes the unit but the local scrap metal recycler has one to help sort out the recycled aluminum. Maybe this will help you out some.

[mxtras]

How about using the surface hardness? I haven't researched this yet, but I seem to recall that the various alooy groups have a slightly different hardness. Of course you would need a hardness gauge, but I see them E-bay quite often.....

Just a thought.

Scott

[bdrmachine]

Thanks guys! This isn't the answer I was hoping for but the replies are appreciated.