Chamfers & Radii – Everything Product Developers Need to Know

Last updated on July 8th, 2024 at 10:09 am

Chamfers and radii are commonly requested features in custom sheet metal fabrication that can occasionally cause confusion.

Whether your sheet metal parts need the angled edge of a chamfer or the rounded edge of a radius, there are a few things you should know.

Chamfers and Radii: What’s the Difference?

Adding chamfers or radii to a part’s edges is a smart way to improve fit, eliminate unsafe edges, and enhance the part’s aesthetic appeal. So, what’s the difference between the two features?

• Chamfers. A chamfer is a 45-degree bevel cut across adjoining right angles. Chamfers are often used to create clearance for mating or connecting parts. We often add chamfers to brackets, enclosures, and faceplates. Chamfers can also simplify the task of manually positioning parts during assembly, and they prevent injury by eliminating sharp edges. (Technically speaking, only corners cut to 45 degrees are called chamfers, though the terms “bevel” and “chamfer” are often used interchangeably.
• Radii. A radius replaces a raw corner with a rounded edge rather than a chamfered edge. Engineers typically design radii to improve a part’s safety and enhance its appearance, though, like chamfers, radii can also improve the assembly and fit of mating or connecting parts

Achieving chamfers and radii

ASM can achieve chamfers and radii using various methods, such as special punch tools, hand-filing, or shaping with a dual-action sander. Tumbling can be an effective way of adding a radius to your part’s edges. For chamfered and rounded edges with critical tolerances, however, machining is almost always the best-and only-solution.

More on that in a minute.

The Secret to Safe Edges and Easy Assembly

When enhanced safety and simplified assembly are important for your sheet metal parts, either chamfers or radii will do the trick. You don’t even need to dimension these features on your print or include them on your model. In fact, don’t dimension your edges-or we’ll quote you for critical dimensions you don’t actually need!

You can further your savings by removing the non-critical chamfers and radii from your 3D model, too. If you don’t do it, we will have to remove these design elements prior to programming our machines.

Safety, simplified

If your sole goal is safety, the simplest way to get your part’s sharp edges removed is to ask. Just add a note to your print asking us to “remove all sharp edges”-and we will.

At ASM, deburring is included as part of our standard processes, so if safety is your only focus, deburred metal edges are usually considered sufficiently smooth.

How to Get Chamfers and Radii with Critical Dimensions

When we see that you’ve dimensioned the chamfers and radii on your print, we trust that those dimensions are critical and that you’ll inspect your parts in accordance with those dimensions.

To ensure precision and accuracy, we’ll engage our CNC machine shop to machine the chamfers or radii. Though machining does add to a part’s cost and lead time, it’s the best process for achieving critical edge specifications and preventing part rejections during inspection.

Get Sheet Metal Parts with Chamfers, Radii, or Simply Safe Edges at ASM

The number one way to get sheet metal parts made your way is to use your print, model, and RFQ to communicate clear specifications and expectations. When we thoroughly understand your goals and requirements, we’re empowered to not only achieve them but also recommend alternative solutions when we identify a better approach.

Talk to our team about your next custom sheet metal fabrication project. Get started by requesting a quote, and we’ll be in touch with you soon!

Sheet Metal Fabrication Chamfers & Radii FAQ

What is the difference between a chamfer and a radius?

A chamfer is a 45-degree bevel cut across adjoining right angles, commonly used to create clearance for mating parts, simplify assembly, and eliminate sharp edges. A radius, on the other hand, replaces a raw corner with a rounded edge, improving safety and aesthetic appeal, and enhancing the fit of connecting parts.

How does ASM achieve chamfers and radii on sheet metal parts?

ASM uses various methods to achieve chamfers and radii, including special punch tools, hand-filing, shaping with a dual-action sander, and tumbling. For edges with critical tolerances, machining is almost always the best and only solution to ensure precision and accuracy.

Should I dimension chamfers and radii on my print or model?

If chamfers and radii are not critical to your design, it is best not to dimension them on your print or model to avoid unnecessary costs. Instead, add a note to your print asking to “remove all sharp edges.” For critical dimensions, include them on your print, and ASM will ensure they are machined to meet precise specifications.

What should I do if safety is my main concern for my sheet metal parts?

If safety is your main concern, simply request to have all sharp edges removed. ASM includes deburring as part of their standard processes, which is usually sufficient to achieve smooth and safe edges without additional specifications.

How can I communicate my requirements for chamfers and radii effectively?

To ensure your sheet metal parts meet your requirements, use your print, model, and RFQ to communicate clear specifications and expectations. Providing detailed information allows ASM to understand your goals, recommend alternative solutions, and deliver parts that meet your needs. Contact ASM to discuss your next custom sheet metal fabrication project and request a quote to get started.