Which statement describes a press fit?

• A. A fit that requires interference (parts are pressed together) with no clearance.
• B. A fit designed to allow loose sliding between parts.
• C. A fit that requires interference (parts are pressed together) with no clearance.
• D. A fit where parts can be assembled with internal threads guiding alignment.

Answer: (C)

A press fit is an interference fit where the parts are sized so they overlap slightly, so they must be pressed together. Because the outside dimension is larger than the bore, there is little to no clearance between the parts once assembled. This creates a joint held together by contact pressure and friction, often used when a permanent or near-permanent connection is desired.

To assemble a press fit, you typically apply a force to press one part into another, or use thermal methods (like heating the outer part or cooling the inner part) to ease assembly. Because there’s no clearance, sliding or easy movement between the parts isn’t possible after assembly.

This is different from a loose sliding fit, which intentionally has clearance to allow movement, and from a fit where alignment is guided by internal threads, which relies on threading rather than interference to hold and align parts. The description that matches a press fit is an interference fit with no clearance, requiring pressing to assemble.