interferencepressfit

Interference fit, also known as press fit or force fit, is a mechanical assembly method where two parts are joined together by friction. This is achieved by designing the parts so that one has an outer dimension slightly larger than the inner dimension of the other. When assembled, the outer part is forced over or into the inner part, causing the outer part to expand slightly and the inner part to compress. This creates a tight, secure connection without the need for fasteners like screws or rivets.

The amount of interference, the difference in dimensions, is crucial for a successful press fit. Too little interference will result in a weak joint that may loosen over time. Too much interference can lead to excessive stress on the components, potentially causing deformation or fracture during assembly. The interference is typically a few thousandths of an inch or hundredths of a millimeter.

Press fits are commonly used in various engineering applications. Examples include fitting bearings into housings, mounting gears onto shafts, installing pins into holes, and assembling engine components like pistons into cylinders. The strength of the joint depends on the interference, the materials of the parts, and their surface finish. Special tools or heating and cooling techniques are often employed to facilitate the assembly process, as significant force may be required to overcome the initial friction. Disassembly of a press fit can be challenging and may require specialized equipment to break the frictional bond.