What does clearance fit ensure when two parts are assembled?

Clearance fit is a type of fit between two mechanical parts designed to ensure that there is a specific amount of space or clearance between them when assembled. This spacing allows for easy movement or assembly, which is crucial in applications where components need to slide, rotate, or be disassembled without difficulty.

In a clearance fit, the tolerances are intentionally designed to prevent any interference between the parts, thereby guaranteeing that a gap always exists. This ensures that even with variations in manufacturing processes, the parts will still fit together without binding or obstruction. The presence of this clearance is particularly important in applications such as bearings or sliders where friction and thermal expansion can affect performance.

While a perfect fit with no gaps may be desirable in some scenarios, it does not represent the characteristics of clearance fits. Similarly, overlaps between parts and overly tight tolerances would contradict the fundamental purpose of clearance fits, which is to maintain distance between the components. Therefore, the defining aspect of clearance fits is the guaranteed presence of space between the assembled parts.