To bend a tube or pipe, you need a die that matches both the cross section of your work, and the bend radius.
Dies are available to purchase here: Edwards Pipe Bender
Edwards prominently displays a tube roller on the baner of its bender die page. Don't be confused; mHUB does not have the roller, and a roller is not likely what you are looking for unless you are making large diameter rings or segments.
You will see that there are hundreds of combinations available, and they are not cheap.
We have the following dies available in the shop.
- 1" diameter tube, 3" radius bend, 180 degrees max.
- 0.5" diameter tube, 2" radius bend, 180 degree max.
- 1.25" pipe, 4.5" radius bend, 180 degree bend max.
There is a lower limit on the bend radius in relation to the cross section diamenter and wall thickness. A rule of thumb is x3; a tube or pipe cannot be bent into a bend radius less than x3 its cross section diameter. A 1" tube cannot be bend into less than a 3" radius.
If you are interested in buying a die, contact the shop manager. mHUB gets a discount from Edwards. If the die is likely to be used by other mHUB members, we will consider contributing to the purchase. We have looked at machining dies, but have found that we lack the tooling and machines to make the process efficient.
Wood and plastic dies lack the strength to bend steel.
If you do not know the difference between pipe and tube, here's the skinny. Tube outside diameter equals (within a tolerance) the nominal size; One inch tube measures one inch on the outside. In most cases, solid rod can be bent with the same die that is specified for tube.
Pipe, in funny. Two inch nominal pipe is neither two inches on the ID or the OD. Not even close or consistantly off across different diameters. Don't try to internalize it, look up the actual OD. Pipe is arrtractive to use because it is cheap and commonly available.
To add to the confusion, bend radius can be expressed in inside radius ( the radius of the inside edge of the tube) or centerline radius (you know). Pipe dies are usually centerline radius, tubing are usually inside radius. If the description does not call out the type of radius, it ususally is inside radius. Watch out - I have found that the Edwards uses centerline radius almost always. And, some pipe dies are usable as the corresponding tube die.
If you think you can use a die that is close to your cross section or close to your bend radius, you are mistaken.
If you think you can straghten or unbend a little bit a bend piece: also, mistaken.
Bending is a learned art. Buy a couple lengths to allow for experimentation and learning.
When prototying, bend with extra length on both sides of the bend and trim after the bend. In production, use stops for consistancy.
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