square tube forming
square tube forming
(OP)
i am forming square tubing out of 5/16" mild steel sheets. i can get the basic shape of the tubing but i can not get the tube to close at the top because of springback. i need to calculate the force required to clamp the tube shut to be able to weld the two flanges at the top together, any ideas





RE: square tube forming
What size do you need? How long and what tolerances, size, straightness and twist?
RE: square tube forming
If you insist on bending it yourself, you will find it's much easier to fixture and weld if you put the seam at a corner, not in the middle of a face.
Mike Halloran
Pembroke Pines, FL, USA
RE: square tube forming
RE: square tube forming
Another advantage is that it is a symmetrical weld case, less likely to distort than only one weld line.
RE: square tube forming
Flores
RE: square tube forming
When this type tube is made in a mill, it is usually rollformed and welded with rollers pressing in on each side. Seems like one could simulate this process on the lengths you want. Proper cooling is going to be the key to not winding up with a horseshoe.
Making two channels and welding from both sides might be less problematic even though you will have twice the weld as pointed out by smcadman.
As to force required, I could probably do it with five four- inch c-clamps.
RE: square tube forming
RE: square tube forming
At the time the only way to make this tube was to direct rollform the rectangular shape and weld. The mill I used originally was Bock Tube which was bought out by Bull Moose.
Previously the tubes with 5/16" 100,000 yield manufactured using (2) C-channels which were welded together. The channels were overbent to about 95 degrees and the weld was lower than the exterior of the tube.
RE: square tube forming
CODE
l l (2 11/16" tall)
l l
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(7 7/8" wide)
Flores
RE: square tube forming
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RE: square tube forming