Understanding Minimum Bend Dimensions

Every week, Team Protocase is bringing you a Proto Tech Tip video, where we’ll give an informative look at a particular aspect of sheet metal fabrication and CNC Machining. This week, Moataz from our Engineering & Design Services team talks about minimum bend dimensions and how far cutouts should be from bend lines.

Watch the full video below – or, if you’d prefer to read his Proto Tech Tip, we’ve got the full transcription below the video.

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Hey everyone, Moataz here from Protocase with your Proto Tech Tip for today. Today, I’m going to be talking to you about minimum bends. 

Here at Protocase, when we talk about minimum bends, we are talking about the minimum distance that a cutout should be from the bend.

So why is this important? If we have cutouts on our part that is located too close to the bend, those cutouts are going to be stretched while the part is being bent, because all of the cutouts are cut into the material when they’re being laser cut. At this point, the part is flat. 

So, when we’re talking about min bends, we are talking about the distance from this face of the part to the corresponding edge of your cutout. These different cutouts are at different distances from the bottom of this part. Or, they have different min bends.

As you can see, these cutouts are perfectly intact and it doesn’t look like there is any stretching happening on them. But, if we take a look at another part with three cutouts that are at three different distances from the bend. One of them is at 0.25″. The other is at 0.20″ and the other one is at 0.150″.

With the first two, we can see that there is no stretching observed in the cutouts. But with the last one, it’s quite close to the bend, and the bottom lip here has been stretched. This might not be desirable for your design. 

So when designing your parts and placing your cutouts close to bends, you might wonder, “How close can I get to this bend without my cutouts stretching?” It depends on the material you’re using, and it also depends on the types of tools that are going to be used to bend that part. This could change from manufacturer to manufacturer, and could also change from machine to machine, as there are multiple methods of bending sheet metal. So, if you want to know more about Min Bends and what are specific values are, you can visit our website. There’s a very helpful table there that can give you all of the information that you need. 

Feel free to check out our website for more information. Be sure also to check out our blog, which outlines many other technical tips. Or, send us an email at info@protocase.com.

Thanks for watching this week’s Proto Tech Tip. I hope this was helpful, and be sure to tune in next week for another Proto Tech Tip!