Burr

Burr

Machining burrs are the unwanted projections of material on machined parts. ... These often sharp, raised bits and pieces that are still attached to the part are referred to as burrs.

Burrs are a rotary analog to files that cut linearly (hence their alternate name, rotary files). They are also in many ways comparable to endmills and to router bits; a distinction is that the latter usually have their toolpath controlled by the machine, whereas burrs are often used freehand. Burrs are an undesired and unavoidable by-product of most conventional manufacturing processes, such as cutting, forming, blanking, and shearing operations, because of the plastic flow of material. A burr is defined as a projection of undesired material beyond the desired machined features (125).