A common practice in part manufacturing involves reducing the chance of damage or injury from sharp corners on components. To remedy this, machinists remove a portion of the 90-degree corner creating a chamfer, also referred to as a bevel. Even though the terms “bevel” and “chamfer” tend to interchange in practice, the two have distinct differences. Let’s take a moment to examine the difference between bevel vs. chamfer and see how CNC machining uses these features when manufacturing a part.
The terms “bevel” and “chamfer” describe the same geometric feature in a part but differ. Defining them both in detail helps discern the differences:
A bevel is a sloped edge between two principal faces of a part and facilitates joining with another. Bevels measure at any angle other than 45-degrees, and they help with wear resistance, safety, and aesthetics. For example, bevels exist in the blades of cutting tools, mirrors, and glass furniture to guard against injury from the sharp edges of the glass.
Unlike a beveled edge that joins one part with another, chamfers transition between two right-angle surfaces of the same part. Chamfers always sit at a 45-degree angle, unlike a bevel. Chamfers remove the sharp edges of a part’s 90-degree corner to prevent injury while handling. A chamfer will also protect the corner of the part from damage, improving the overall integrity of the part.
The machinist will use a chamfer mill or “cutter” when milling the part to create bevels or chamfers in machined parts. The bevel may take more passes to make, with a typically larger area to cut than a chamfer, but this is subjective. Additionally, double-chamfer end mills cut chamfers on the top and bottom of a workpiece without flipping it over. Machine shops find these tools very versatile as they can use them for chamfering, beveling, deburring, spotting, and countersinking. However, bevels and chamfers can add costs to manufacturing your part, addressed next.
An example of a bevel on the left and a chamfered corner on the right.
Obvious reasons exist for using bevels and chamfers to protect the part and its users. These features often get included more for aesthetics than function, however, and they can increase the production costs of a part.
Some practical questions to ask before including a bevel or chamfer in a design:
Features like bevels and chamfers require additional time during manufacturing. Even a 10% increase in time per part can quickly add up when multiplied over the number of production parts. Reconsider extraneous features if they do not serve any necessary function or purpose. The specified tolerance for the bevel or the chamfer should also undergo some review. Machine shops take more time manufacturing and checking tighter tolerances, which also adds expense to the production of the parts.
While one should scrutinize the aesthetic uses of chamfers to avoid unnecessary manufacturing costs, some applications of chamfers exist where the cost is well-justified. For instance, countersinking a threaded hole can help avoid the creation of burrs during tapping that could affect how two mating surfaces will seat together. Countersinking will also help bolts align correctly when they start and avoid expensive cross-threading errors during assembly. For some holes, such as aircraft rivets, precise countersinking is so essential that they require critical tolerances to ensure an adequate amount of available mating material for a secure connection.
Another cost effective use of chamfers is on the internal features of a milled part. Designing chamfers into a part's features instead of squaring the corners will lessen that part’s manufacturing costs. The chamfers will reduce the time it would take to cut right angle corners into the part, and allow for the use of less expensive tools. Internal chamfers will also help avoid dirt and waste from accumulating in the part’s corners.
Considering all of these issues before designing a bevel or chamfer into a part offers advantages. If a design doesn’t need these features, their exclusion will simplify manufacturing, saving time and money. On the other hand, if a design does need them, one can still reduce the impact on the production time and expense. One way involves providing generous tolerances, simplifying the fabrication of bevels and chamfers if exact size isn’t critical. Another option is to remove the chamfer features altogether from the CAD model and include a note on the 2D drawing instructing the machine shop to “remove all sharp edges.”
A reliable machine shop can help determine whether or not to include bevels and chamfers into part design.
Creating a good design isn’t just about engineering a functional part. It also includes efficiency during manufacturing. The machine shop building a part provides the best resources for design advice.
One of the first helpful tools available from a machine shop is their online part analysis system. After uploading a CAD model for a quote, their analysis tools will indicate whether or not they can machine the part. If features preclude the part from fabrication, they will issue a report so that customers can make any necessary changes. Additionally, the personnel at the machine shop will answer questions about a design and what it will take to manufacture.
At Plethora, we specialize in manufacturing precision parts using the industry's most advanced CNC machining equipment and software. We make it our goal to manufacture your part at the highest quality and functions. In addition to our online analysis and ordering tools, our staff comprises engineering and manufacturing experts ready to help you achieve your goals. We designed our online DFM and quoting systems to immediately receive your data so we can begin working together on your next project. To get started, upload your design files to Quote My Part or call us at 415-726-2256.
The Plethora Team
The Plethora team is your go-to CNC manufacturer for hardware done right the first time. We have the tools and experience needed to create high quality custom parts quickly and with precision, whether you need a prototype or production run.