[Devildog2076]

Hi: I am going to a manufacturer tomorrow and he has said I can take as much aluminum as I want. How do you know if its 4,5 or 6 series if he doesn't have it id'd or segregated? Is there a test or is it stamped? I know these are stupid questions but just bear with me please.

[weldin mike 27]

Whole sheets or lengths will have a label. If he is selling new stuff cut up, it's his responsibility to transfer that label to the leftovers if he sells a bit with the label on it. If he doesn't, he's a dangerous fool.

[weldin mike 27]

If it is for practice, take what ever you want and weld your heart out. However, don't make anything out of it that could hurt someone if it fails, unless you can see a label on it. I'm fairly sure that anything short of a mass-spectrometer can tell you for sure what you have. Maybe I'm wrong.

[Devildog2076]

probably not a good idea to build tree stands with aluminum unless strength/type is known

[MinnesotaDave]

Hi: I am going to a manufacturer tomorrow and he has said I can take as much aluminum as I want. How do you know if its 4,5 or 6 series if he doesn't have it id'd or segregated? Is there a test or is it stamped? I know these are stupid questions but just bear with me please.

Large scrap yards often have a "gun" that tests metal for recycling.

They are expensive, so you won't find them just any old place though.

As said by others, don't use it where someone will get hurt if you don't know what type aluminum it is.

[angus]

why don't you ask him.

[Otto Nobedder]

Drop evenly cut pieces on concrete. 3xxx and lower will sound dead, 4xxx will sound dull, 5XXX will ring. 6xxx varies depending on temper, but will always sound sharper than 4xxx.

This takes practice, but if you have rods in different alloys, like 3003, 4004, 5356, drop them one at a time on the concrete, and note the difference in sound.

This is only a rough judge, based on the hardness of the particular alloy, but will get you in the ballpark.

Steve S