Of all the questions we get from our sheet metal customers—the one that tops the “most asked” list—is how to design a bend radius. We talked about this dimension in a previous blog post and video that’s worth a look, but here are some important specs to help you with your parts.
Forming and the Bend Radius
It all starts with understanding the process we use to form your parts. When you form sheet metal on a press brake, you don’t get a perfect, straight corner. Instead, a curve forms where the die presses the metal. When you divide the length of that internal curve by two, you get a dimension called the bend radius.
Starting with a Flat Part
First, if you haven’t done it already, we take your design and unfold it into a flat pattern. We do this because that’s how all sheet metal parts start—as a single slab that we cut and form based on your design. If we don’t get it as a flat design, that adds time to the process.
Forget What You Learned about the Bend Radius
In school, many designers are taught that the bend radius is the same as the material thickness of your sheet metal. But it doesn’t have to be. In the video below, our sheet metal is .074” thick. In an effort to speed production and maintain the structural integrity of your part, we use a bend radius of .030”—the industry standard.
There is virtually no difference between the two versions. The length of each side stays the same, and only the size of the curve has changed. It’s the same part, but it costs less because—without tool changes—it won’t take as long to make your part.
Speeding Up Manufacturing
So, if you need your parts back quickly, using a standard .030” bend radius will help. You’ll get a strong part, and it might even save you some money.
For more helpful sheet metal design tips, download our Design for Manufacturing (DFM) Guide.