What is a burr in metalworking?

In metalworking, a burr refers to a rough edge or a raised lip that is left on a workpiece after it has been cut or machined. This occurs due to the material not being entirely cleanly severed, often as a result of the cutting process or tooling that does not leave a smooth finish. Burrs can vary in size and shape depending on the cutting method and the material being worked, and they can pose issues such as affecting the finish of parts, leading to potential injuries, or causing assembly difficulties. The removal of burrs, often referred to as deburring, is a crucial step in the manufacturing process to ensure safe and smooth functioning of metal components.

The other choices do not accurately define a burr in the context of metalworking. For instance, while a grinding tool is essential in machining processes, it does not define what a burr is. A protective coating on metal serves a different function, primarily aimed at corrosion resistance, not addressing the surface finish left after machining. Lastly, measurement of material thickness does not pertain to the characteristics or definitions associated with burrs in machining contexts.