What tool is used to measure the internal size of an object?

Inside calipers are specifically designed to measure the internal dimensions of an object, such as the diameter of a hole or the width of a groove. They have two curved legs that expand within the object being measured, allowing for precise readings of interior sizes. This makes them ideal for tasks where external measuring tools cannot be applied effectively.

While other measuring tools like outside calipers and micrometers serve different functions—such as measuring external dimensions—inside calipers are uniquely focused on internal measurements. Therefore, their shape and design are tailored specifically for this purpose, ensuring accurate and reliable readings for internal dimensions.