Red Seal Machinist Practice Exam

In machining, what does the term 'interference fit' refer to?

1. A fit that allows for easy assembly and disassembly

2. A fit that ensures tight assembly without play

3. A fit that requires heating of components

4. A fit that is loose enough to permit movement

The correct answer is: A fit that ensures tight assembly without play

In machining, 'interference fit' refers to a fit where two mating parts are manufactured to a close tolerance such that when they are assembled, one part is larger than the other. This results in a tight assembly with no play, necessitating force to fit them together. This type of fit is crucial in applications where a secure connection is required without any gaps that could lead to movement or vibration between the components. Interference fits are often used in applications like securing gears or pulleys onto shafts, where a snug fit is vital to ensure reliable operation under load. This is why the correct answer emphasizes the aspect of ensuring tight assembly without play, reflecting the essential characteristics of an interference fit in machining contexts.