Chapter 29: Inspecting for Burrs and Sharp Edges

OVERVIEW

Each shop seems to have a slightly different way of looking for burrs, as well as differing expectations of what burrs are and degrees of acceptability. Each inspection technique yields different results. While no single way is best, there are inspection methods that are fast, exceptionally accurate, quantitative, and result in a pass-fail conclusion. This chapter provides an in-depth look at the many aspects of burr inspection. The terminology is consistent with "An Integrated International Standard for Burrs and Edge Conditions" (Gillespie 1998).

There are six elements of burr inspection or measuring systems. They are:

• existence of a standard for defining pass or fail

• consistency in employing the method and standard

• training of inspection workers

• equipment calibration

• knowing the statistic of most significance

• documentation of results.

These elements are discussed throughout this chapter. Whichever technique an inspector might use, it is important he or she base it on a written standard, employ it consistently, perform it with an understanding of what the results imply, employ it with calibrated tools, and document the results. These quality issues may seem obvious; however, they might be overlooked in something as "simple" as burr measurement.

In fact, establishing a burr's size requires an inspector make more than one measurement per feature, and users will find it a challenge to replicate a measurement. This shows that a single measurement will not be sufficient to establish what is a normal burr size.

29.1 BURR AND EDGE STANDARDS

As discussed in Chapter 2, some companies have...