Why is it important to define tolerances in design?

Defining tolerances in design is crucial because it ensures that parts fit together properly and function as intended. Tolerances specify the allowable differences in dimensions between parts, which is essential in manufacturing processes. If components have the exact same dimensions, they may not fit together due to imperfections from the manufacturing process or thermal expansion. By establishing tolerances, designers can account for these variations, allowing parts to be assembled without issues while maintaining the functionality and performance of the final product. This is particularly significant in mechanical assemblies where precise interactions between components are necessary for their operation, such as in engines or machinery. Properly defined tolerances help to prevent costly rework and ensure reliability and safety in the product’s use.