January 13, 2022

Cutting Corners on Sheet Metal Parts: Chamfers & Radii

By Protolabs

Incorporating design enhancements to your sheet metal parts serves a variety of purposes beyond adding aesthetic value. Although, some features do tend to give sheet metal parts a highly cosmetic and finished look.

Two commonly used and recommended sheet metal design features on the corners of a square or rectangular part are chamfers and radii. Either can eliminate what would be sharp and raw or semi-raw cut metal corners and replace them with either a rounded corner—a radius—or an angled or beveled corner—a chamfer.

There are a lot of reasons why you should incorporate chamfers or radii in your sheet metal designs. Here are five big ones.

Chamfers, like the ones you see on many of these bends, eliminate sharp, dangerous corners.

Safety First

Most importantly, raw-cut edges on sheet metal corners are extremely sharp, making the part dangerous to handle. Laser cutting leaves a bit of slag on the edges and punch cuts leave a sharp edge and a small protrusion where the tools slice the metal—neither of which are ideal to handle as is.

Deburring cut edges is standard practice here and eliminates some of the risk of injury for both our employees and our customers. However, an easier and much safer fix is simply to round corners with radii or bevel corners at an angle with chamfers. Do that and you’ll have no dangerous sharp corners and you won’t have to buy bandages in bulk.

Mating & Connecting Parts

Sheet metal parts are often among the last pieces of the product development puzzle, enclosing or connecting other machined or  molded parts, or off-the-shelf products. The most common sheet metal parts that incorporate chamfers or radii are brackets, enclosures, and faceplates, most of which typically connect to other parts of an assembly.

Clearance

It’s not uncommon for a sheet metal part to include a radius or chamfer to help it fit easily inside another component. Sharp 90-degree corners don’t always allow for easy clearance when trying to affix or nestle one part inside or within another.

Not only do chamfers and radii improve part function, but adding these features can boost a design's aesthetic value.

Aesthetic Value

As mentioned above, while safety is the most common reason to include chamfers and radii on sheet metal parts, these design elements also offer a cosmetic, professional, finished look. These two design features are typically simple enough to incorporate and shouldn’t come at an astronomical cost to you in comparison to other more elaborate elements. So, you get maximum bang for minimal bucks.

To Chamfer or to Radius?

That is the question. Here are a couple of considerations to keep in mind if you’re unsure whether to opt for a rounded radius or a chamfered edge for your metal parts. 

  • Chamfered edges can only be achieved through machining, whereas a radius can be done in various ways via our sheet metal fabrication methods. If you have a preferred service (machining vs. sheet metal fabrication), that may dictate your decision.  
  • Keep in mind, only specific angles are available for chamfered edges. We currently offer 60, 82, 90 or 120-degree angled edges for parts.
  • Adding chamfers can add additional time and/or cost for your part, so keep in mind that radii are typically the less expensive design solution.

Our application engineers and customer service team members are here to help you. Don’t hesitate to reach out  if you have questions regarding any upcoming project.