Which term describes a raised feature around a perforation?

• A. Gasket
• B. Lip
• C. Burr
• D. Ridge

Answer: (C)

A burr is a raised edge around a perforation that forms when material is cut, punched, or drilled. The shearing action pushes material outward, creating a small protruding edge or roughness around the hole. This is the exact feature described by the term burr. Gaskets are sealing rings used around holes, not raised edges of the hole itself. A lip is an intentional edge that helps seating or stopping, not specifically the edge around a perforation. A ridge is a continuous raised line elsewhere on a surface, not the edge surrounding a single hole. Burrs are typically deburred to ensure smooth mating and prevent snagging or leakage.