what kind of alumunim do i have ? ?

[davidh]

i have a half dozen medical home care oxygen tanks that are alum in color with green top section. . . for obvious reasons. they are scrap so i have attempted to cut them into smaller pieces so they will fit in my crucible for melting. they are about 4 inches in diameter with approx. 1/4" wall thickness.
very forgiving when i try to flatten the rings i have cut. . . and they don't break or even crack when squeezed down in 180 degrees tight bend. . .

what grade would any of you knowledgable guys think this stuff may be ?

[tdmidget]

Since it is not a cast alloy you are wasting your time melting it, If you want to make castings, start with castings. They would normally be 6061 but there are some out there of 6351.

[Grind Hard]

Medical-grade Aerospace Billet, of course.

I'm surprised you even have to ask.

[flylo]

Ever see that youtube on how they make scuba tanks? Amazing!

[JoeLee]

Ever see that youtube on how they make scuba tanks? Amazing!

Please post the link.

JL.........................

[davidh]

dang, i thought i reallly had something here. well, you suppose they would work for crafty kind of castings ? like "lost foam" stuff ? ;gheeze, ive got a lot of cutting time into them, hate to see that all go to waste .

[EVguru]

People often have trouble with machining castings made from extruded alloys.

The usual trick is to add a little copper.

Search the casting forums for details.