Bending and Stretch Forming

[barley]

What is the difference between bending and stretch forming?

[13architect]

Push bending
Single axis controlled
Only 1 radius can be bent at a time
Can perform close proximity multiple plan bends
Inexpensive tooling

Rotary draw bending
Single axis controlled resoltuion to .1 degree
90 degree maximum bend per bend
Only 1 radius can be bent at a time
Bend precision is good
Moderate tooling cost

3-Roll bending
Can roll full 360 degree part
Large radius bending only
Limited to single plane bending per cycle
Bend precision is very good
Moderate tooling cost

Stretch Forming
Elongation control for unparalleled accuracy and consistency
Non-symmetric profiles are readily fomred without twist
Maximum bend radius is unlimited
Minimal surface distortion and traffic marking
Maximum diameter 180 degree bend at full tonnage = 70"
Minumum diameter 180 degree bend at full tonnage = 15"
Moderate tooling costs

[AlumPhys]

It would definitely appear that stretch forming has some great benefits, especially when requiring minimal surface distrotion and repeatable bends.

Great info, thanks!

[M.E.1209]

I have multiple extrusion profiles that are stretch formed. It's a great technique, especially in my application in the C-arm business (MRI/CTScan). It's the only technique that we could find after years of R&D that allow us to have repeatable bends, highly precise and controlled deformation (very, very minimal). If anyone is thinking about having their products formed, I would highly suggest finding an extruder that can do this process in house. That way they can control the material composition, temper and quality of the part.

[metalengineer]

We also use the stretch forming process for our aluminum boat gunwals. Integrated into our manufacturing process nearly 7 years ago, it's made huge improvements to our product quality and assembly times in the factory.

I also agree that using an aluminum extruder that can stretch form in house is critical to the success of your component(s). Being able to stretch form in a T4 condition (temper achieved after extruding) and than artificially aging is a huge benefit

[Brad]

I've never heard of stretch forming, that's pretty cool!