What is a 'fillet' in the context of engineering design?

A 'fillet' in engineering design refers to a specific feature that creates a curve at the interior intersection of two or more surfaces. This curvature serves several important purposes, such as distributing stress more evenly across a joint, reducing the risk of stress concentration that can lead to material failure, and facilitating ease of manufacturing. Fillets are often used in mechanical designs to improve the flow of fluids around components and to enhance the aesthetic appearance of a product.

By smoothing out sharp corners, fillets can also make parts easier to handle and assemble, while also contributing to better performance in applications where fluid dynamics are considered, such as in aerospace or automotive engineering. The incorporation of fillets is a common practice to improve both the functionality and durability of mechanical components, making them an essential consideration in the design process.