Deburring is the process of removing extraneous material leftover from machining. This material is not considered part of the design and cause a variety of issues if they come loose later. Issues may include plating voids, cosmetic paint imperfections, mechanical damage, or electrical shorts in some products. Burrs must be removed manually using various hand tools such as files or razors blades or mechanically from processes such as tumbling. Although a requirement for burr removal is not always explicitly stated on part drawings, burrs are almost never considered acceptable on a finished part; as such, deburring is industry standard for machining.
Edge-breaking involves removing sharp edges on machined parts typically to prevent cuts. Various hand tools and mechanical methods are used for edge-breaking, similar to deburring. Edge-breaking is generally considered industry standard for machined parts, so it is not always listed as a requirement on the part drawings. Edge-breaking is somewhat more subjective than deburring. For example, it may not be necessary or practical to break the edges on some internal features of some parts. Also, some part features require sharp edges, and engineers will typically add drawing notes specifying not to break the edges on those features.
Deburring and edge-breaking are critical to making tight-tolerance parts. Even the smallest burr can cause a shift of 0.001″ – 0.003″ on a part when it is loaded into a CNC machine for secondary operations. And sharp edges invariably result in cuts for the machine operator.