520-294-5600 4dinfo@nanometrics.com

Measuring edges and corner radii with 4D InSpec

The Superiority of 3D Measurements

“Breaking” an edge refers to rounding a corner or adding a flat chamfer. Edge break is often done to improve the longevity of a part, or improve the safety of humans handling the part. Sometimes a chamfer or rounding ensure proper part performance, for example when the chamfer is done to countersink the head of a screw in a hole.

Having the right amount (and consistent) edge break or chamfer is critical to these objectives, and also to aesthetic finish—but these features are notoriously hard to measure.

Common quality checks involve using a paper (or cardstock) corner gauge, which is visually compared to the part, or using a 2D profile trace. In both cases, alignment which produces a profile perpendicular to the edge and its adjoining surfaces is troublesome, uncertain, and time consuming.


In this measurement of a curved radius edge, we drew several profile traces at different angles, demonstrating how traces that aren’t perpendicular report the incorrect radius of curvature—demonstrating the hazard of relying on a 2D measurement.


Making the measurement right

As you might imagine, a 3D measurement simplifies the process, if your software will properly assess the important characteristics involved: the location and comparative slope of the two adjoining surfaces—not necessarily 90 degrees to each other—and the location of the broken edge, and its direction in respect to the surfaces.

That is, even though you have a 3D measurement, it’s important to find the center, or average center, of the edge break area. So your software needs to be intelligent enough to separate dings, nicks, and incidental surface planes from the dominant surfaces in the measurement.

Using a smart algorithm, analysis software can plot regions, which then serve as averages.


We’re working on it

Because 4D InSpec is a quick, shop-floor measurement technique, manufacturers of many types would benefit from being able to measure edge break with it.

To help those customers, we are in the process of testing our Edge Break application for 4D InSpec.

Do you need Edge Break?

If this is something you can use, you might be interested in being one of our Beta Test customers. As a beta test customer, you’d be able to use the application early and provide us contextual feedback that will enable the software to be finalized as an effective product for you and others.

Review our research

Here’s a paper we presented to SPIE this year on edge break and chamfer measurements. As a science and engineering technology company, we have been a Corporate Member of the Society of Photonics Industrial Engineers from the beginning.

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