aluminum tube bending minimum radius chart

8×4 Aluminum Tube Cracking 8×4 Stress-Relieved Aluminum TubeĪs you can see, determining the minimum bend radius for a piece has many factors to take into account. In the end, this caused a much improved final product for the customer with no additional material cracking issues. To solve the issue, the material was sent out to be stress-relieved before rolling was continued. However, the aluminum tubing began to crack, possibly due to age-hardening coupled with the tight radius. The same tubing rolled in carbon steel could be pulled much tighter. One previous job which provides a good example of this used some 8 x 4 aluminum tubing rolled the hardway to a 16 foot radius. Material used can also change the minimum bend radius. Increasing the wall thickness on a tight radius bend generally improves the final quality of a rolled tube as well as lowers the minimum radius a piece can be rolled with minimal distortion issues. Another important factor to consider when looking at pipe or tubing is the wall thickness of the piece to be bent. In these cases, the minimum radius will likely need to increase beyond a 3D size.

While it may not be a minimum for every bender, a 3D bend radius is a commonly used starting point for minimum radius bends.Īs a piece size gets larger, pre-made tooling for tight bends will be less common.

For tight rotary draw bending, maintaining a bend radius that is a whole number multiple may increase the capability of the steel bender to meet your needs. So, even though it may be possible to give a piece a 2D or 3D bend, a 3.5D bend may be more difficult because the tooling is not on hand. This type of bending is usually performed on a rotary draw bender for speed and precision, which requires specific tooling built for each bend. 2D = 4 inches, 3D = 6 inches, and 5D = 10 inches for a 2 inch diameter pipe. In these cases, the 2D would reference a centerline bend radius of two times the diameter. For example, on a 2 inch pipe elbow, common bend measurements may be referred to as 2D, 3D, or 5D. In some instances, a rough guide for minimum radius bending would be to use a multiple of the piece diameter. A 2” carbon steel pipe will have a different minimum radius from a thin wall 2” aluminum tube. There are many factors to take into account when determining the minimum radius such as the material composition, shape, and size. In some instances, an estimator can quickly say yes or no based on prior knowledge and bending experience. Often, in the rolling and bending industry, we field requests asking about the minimum radius to which we can roll or bend a piece.

Aluminum tube bending minimum radius chart