Hello,
I would like to know how to determine when to bend tubing and when to cut/miter/weld to achieve an angle in a structure.
I have a gut-feel that a slight bend is generally stronger than the same angle achieved by welding, since the metal hasn't been affected by heat. But I imagine that for a final quantifiable determination it all depends on the radius of the bend, material, wall thickness, the method for bending, available tools, the way that the finished piece is stressed in use, etc... If there is any general rule of thumb or a method for making the choice, I would very much like to find out what it is.
In case this question is too general, I have a simpler and more immediate one: I need to put a 13 degree bend on a 0.750" square aluminum tube (6061 T?) with the wall thickness of 0.120". Should I miter and weld, or should I bend it? I do not have a tubing bender (yet?), but I do have a TIG welder. For a bend this slight, do I need to borrow a bender, or should I just tweak it by hand around a lally column?
FWIW, it will be the top tube in a triangular cantilever structure, and it needs to be bent to clear another element of the structure. Therefore, the dominant stress applied to it will be elongation.
Any information that the group is willing to share on this subject would be greatly appreciated. A referral to a particular textbook or site for some reading is equally welcome.
Thanks!
-- Ilya