Best aluminum alloy for bending?

[k_sims]

I have embarked upon a deceivingly challenging project that involves bending 3/4" thin walled aluminum tubing into circular shapes about 36" in diameter. I'm having a heck of a time finding the right material and was wondering if any experts out there knew from experience what the best aluminum alloy for this application would be? My plan is to pack the tubing with sand and hand bend it cold around a jig.

[FusionKing]

I have found that 6063-T4 bends rather nicely.
In your case it would depend on if you can get it it your size or not.

[SundownIII]

"hand bend it in a jig"

Good luck, but think you're barking up the wrong tree.

Sounds like a job for a good roller with good dies.

[Keith_J]

Temper over alloy. Any 6000 will bend nicely in the T0 condition. Thin wall tube LOVES to collapse. Have you tried filling the tubes with sand/wax/lead before bending? This will limit collapse, depending on how tight you bend. Start with sand, move to wax if it still collapses or even lead.

You will need more effort to bend filled tubes but the filling will limit buckling.

[FusionKing]

I wanna know the wall thickness myself before I comment too much.

[walker]

I don't think you can possibly end up with a quality product bending alum tube by hand at 36"d circle. I have bent plenty of metal and I can tell you this is not as easy as you might be thinking. I second the roller. If you are intent on trying go with the lower 'T' numbers, as this indicates hardness. commonly available T-6 in an .065 is not going o be happy about this.

[SundownIII]

Heck,

I'd buy one of the Harbor Freight rollers and get the guys at Swag to make me up a set of dies/rollers before I'd ruin a lot of tube trying to hand bend it.

Be the cheapest solution, but still not the best.

[crabber]

This link has good info for aluminum:
http://aluminium.matter.org.uk/aluse...16&term=marine

-Ian

[jhwelder]

Anneal it. Take the temper out of the side walls. I would try to leave the temper in the inner and outer radius' . It will be soft and it should bend. As long as this is not a load bearing application.

[fdcmiami]

i would definitely opt for getting someone to roll them if there are a bunch. as to the thin wall tube, why make it more difficult than it has to be.

i have roll formed aluminum rings using 1" schedule forty 6063 T0. smallest were 24 inch mean diameter. i did it by stacking three pieces of 3/4 in plywood and cutting out a circle 22 in's in diameter. i set this on a table that was fixed to the floor. screwed in a stop that allowed the pipe to sit snugly between it and the plywood disc. then i took an over sized piece of al and started walking it around the plywood. when i got to the other side i just came up higher and passed over the point where my stop was and continued a short way. then i cut off the overage placed the ring on an x formed to the inside dimension of the ring and cut it at the overlap point. cut it whichever way is easiest for you.

i never had much luck with sand, tried it a couple of times didn't seem to help.

it is very simple to do. the only difficult part is hitting the springback number for your alloy. 36 inches i would not hesitate to hand form. that is a very large radius for what you want to do and even the thin wall would probably work without much problem. still and all you might be better off having someone do it for you; although i have done a lot of cold forming i would not do it now unless it was unavoidable.