Protocase Resources

The information below is intended to be helpful for customers who wish to learn more about enclosure design. Also, please use our online support if you have questions for our expert design staff.


Internal Bends

In sheet metal fabrication, bending is the critical operation for creating the custom parts required. Our Sheet metal is bent with a press brake or folder in order to form custom electronic enclosures and parts.

Protocase Tech Tip Video

An internal bend is a bend that is placed on a particular area of a part where material surrounds the bend, rather than a typical bend, which is placed at the outermost edge of a part.

An inset bend is very similar to an internal bend, except an inset bend is inset a small amount from the part edge, instead of being completely inside the part profile.

Internal Bending Process

In order to create an internal bend, we section the upper and bottom tooling of the bending equipment in order to line the tooling with the internal edge flange.

With the tooling sectioned, it will only bend the part of the material with which it makes contact.

Sequence of Internal Bends:

Internal Bend Samples:


Internal bends can be created on many types of sheet metal, including aluminum, cold rolled steel, galvanneal and stainless steel.


In order to create an internal bend, the cutout of which the flange gets bent must be large enough to fit half of the bottom tooling that will be used.

The bend width must be smaller than the smallest die available.

Our Engineering & Design Services can access your design to ensure the internal bend in your design is achievable.


Parts with internal bends can be treated with any of our finishes, so long as the part meets the minimum and maximum dimensions for the particular finish you choose.