Bending aluminum tube 1

[jplot]

I have not met with any success in trying to bend 5/8 (.625) OD, 6061 aluminum tube with a wall thickness .035. I have tried both hot and cold bends and the inside of the 70 degree and 20 degree bends always kinks badly which weakens the overall strength of what I am making.

I am wondering if a thicker wall thickness would solve the problem or perhaps using 2024 or some other grade of aluminum tube. I am trying to make my object as light as possible and the .035 is perfect if I could just get the bends to shape up.

I have bent a lot of .375 aluminum tube with .035 wall and the same angle of bends come out perfect but that no doubt is a different ballgame.

All tips and advice will be appreciated.

 

[unclesyd]

Comeback with the centerline radius of the bends and how you are attempting to make the bend.
Also give the temper of the 6061 Al.

It looks like you are might have to draw bend the tube. The softer tempers will help.

 

[btrueblood]

As unclesyd said, but more importantly: you need to know what the temper of the 6061 is. You'll probably need to have T4 temper to make tight radius bends. But, T4 material that is a year old may not be T4 anymore (there's a reason it's called an age-hardenable alloy).

 

[AlanD]

Fill the tube with dry sand and seal the ends before attempting to bend. The sand helps prevent the tube crushing or kinking, but because the sand is lose it still flows allowing the tube to bend.

 

[EdStainless]

Or better than sand, make the bends on a bender with an ID mandrel. (Indium also makes good filler for bending)

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[jplot]

Many thanks to all who took the time to reply to my problem of tube bending.

The radius of my bends are in the neighborhood of 2 inches and I have no idea what the temper is of my 6061 aluminum tube. I alwasy thought that the tempered stuff was the 2024?

I have tried the "filling with sand" thing and will do some more testing but that needs a lot of prepping.

I have been playing around with my own bench setups as I do not want to plunck down a hundred dollars or more for a bender that is not going to work and I have not been able to find a rental place that carries one.

Since reading all of your comments I did some more thinking and went to Ask Jeeves, and dammed if it did not come up with a very fine site when I asked the question of Bending 5/8 aluminum tube. Good info there and diagrams of simple bench setups. With my new setup at the bench I am haveing some success with a lot of heat at the point where I am making the bend. My torch is supposed to be hotter then propane and is in a yellow cannister??? Don't want to go with my acetalyn (spelling?) as it is too easy to melt the aluminum with that.

Thanks agin. This site is great with people helping people.

 

[MetalsInc]

If you are heating 6061 you really need to know what is going to happen to that region. You'll be changing the temper of bend. You might sucessfully bend it, but your properties will be changed. Look at doing it right with an ID mandrel (or sand).