Accuracy is one of the most important things in the engineering world. In many cases the tolerance is just a tiny fraction of a millimetre; anything more can lead to disastrous consequences. As a result, you need to think about the various factors that can lead to inaccuracies. Springback should be near the top of the list, especially with processes like tube ring rolling or bending metal sheets.
What is it?
Every material has a natural state. In most cases, if you alter it, the first reaction is to try to return back to the original. That happens when you bend different types of metals. The bending process causes a change in the molecular density because it makes it stretch and shrink. When you remove the bending force, it tries to go back.
The crucial thing to keep in mind is the material can’t go completely back to normal because of harder, unyielding material around it. So, you only get a certain degree of springback. It varies depending on materials, especially the yield strength. The design specifics have a big impact too. Typically you get less springback when you have a small bend radius because you’re not imparting as much stress on the material.
How to overcome it?
Answering the question in the title of this article, the best way to tackle springback is to plan for it and compensate. For example, if you have a material that in tests deviates by 2 or 3 degrees from the bend, you can overbend by the same amount. As a result, when it tries to return to normal, you should end up with the exact bend degree you want.
With tube ring rolling or other processes, you should always start by doing test bends. Keep in mind that properties can vary in different batches of materials. Even if you order the exact same grade of material from the same supplier, there will be marginal differences. Therefore, always test the exact bends you need using a sample from the same batch.
When you do test bends, it is important to keep a clear log. Make sure you record the batch number of the material. Then, try bends at different degrees to see how much springback there is. All of this information will give you reference points for bending projects.
It’s also a good idea to try to get the bend you want first time. Many materials suffer from work hardening, where strength increases as you are working it. It can lead to big problems with springback if you have a material that hardens; it may mean secondary bending is not possible or will cause defects.
Finally, make sure you have the right equipment. This includes a quality tube bender and die if you’re dealing with tubing. Just remember springback is a natural occurrence; if your bends aren’t the exact degree you wanted, it’s not an issue with your equipment.
Talk to us about tube ring rolling and how we ensure accuracy
When accuracy is absolutely crucial, it pays to work with experienced experts. Multiform Tubes Engineering Ltd is one of the best specialists in our field. We’ve got incredible experience, having previously worked with everything from copper to titanium. Even better, we have an impressive array of equipment and tooling. As a result, we can set up to provide the best solutions.
Speak to us if you want exceptional services. We can provide tube ring rolling, bending, end forming, and more. In fact, you can arrange a specific package if you need more than one service. We can adapt the tubes for you so they are ready for the next stage of your project, including assembly or installation.