Trying to twist square tubing

Looking to see if anyone has tried to twist 2" thinwall square tubing.
I have a project where I need to put a twist into about a three foot
lengths of 2" square tube.
I'm thinking that if I insert a loose fitting round pipe inside the
square tube and would then pack the tube with sand and weld caps on
each end that this would stop the tubing from buckling. I have a large
old pipe threader which I'm going to try and do this cold also since it
is rather large of an area to try and heat up uniformly at once.
Any thoughts or other ideas and practical experience would be
appreciated.
Reply to
pccruiser
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You'll need a LOT of torque!
I haven't twisted tube, just flat or massive square. The trick to use some tube to keep the thing straight is right. In your case, I'd put just some round inside of your square tube. No sand, no caps. If you weld on caps, you need much more force and the twist won't be even. You could also slip some round tube over your square tube if you haven't something that fits inside. Doesn't make a difference.
HTH, Nick
Reply to
Nick Mueller
I would try it with just the pipe inside the square tubing first. If it works it will be a lot less work. And I think it will work.
Dan
Reply to
dcaster
Shoot, every time I try to bend one of those straight it gets twisted! :-)
GWE
Reply to
Grant Erwin
And mebbe heat it up w/ a rosebud O/A tip. Sposedly yer not sposed to use rosebuds on B tanks, but if you have a flash suppressor in line, doing it on a full tank should be OK. I've done it. Or preheat some other way.
Reply to
Proctologically Violated©®
It will twist nicely if you keep it under tension. Doing that is a bit tricky. Find some 2-1/2" x .250" wall square tube, cut some 1/2" slices, weld these over the 2" tube. make a 3' long fixture out of 2 pieces of heavy wall 2" pipe (or similar strength) along with some end caps. You will need to shim the end caps to start the twisting with the tube held snugly. Putting enough torque on it is your problem!
pccruiser wrote:
Reply to
RoyJ
I've done it with smaller thinwall steel by putting a bolt through holes in either end and mounting one set firmly to my work table, then taking the burner out of my forge and giving it a couple of passes with that, but it has a tendency to spiral at the same time. I think that if I were able to put it under tension as suggested above that that might not happen. You could probably wind up doing just as well by fitting a round pipe down the middle and putting the bolt through just beyond it. If it begins to scrape too much, heat the whole thing up and stretch it out a little, let it cool some and try again. Can't promise all that much for strength, but it would probably do for decorative work, which, since you haven't mentioned concerns about the seams weakening, I guess is what you're up to. Just dont heat
it too much, and turn slowly. GCC
Reply to
gcc
Can't be too hard. Every time I loan my post hole digger, it comes home with a twisted PTO shaft. :)
--Andy Asberry recommends NewsGuy--
Reply to
Andy Asberry
And I'd cut it to length *after* I twisted it...
Reply to
Jim Stewart

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