Which measuring tool focuses on measuring the curvature of objects?

Calipers are specifically designed to measure the distance between two opposite sides of an object, which makes them ideal for measuring the curvature of both internal and external surfaces. The design of calipers allows for precise measurements, capturing not just straight dimensions but also the curves of rounded objects, which is essential in many applications such as machining and fabrication.

While thickness gauges measure the thickness of materials, depth gauges are used for measuring the depth of holes or recesses, and wire gauges determine the diameter of wires, none of these tools are primarily focused on the curvature of objects. Calipers stand out for their versatility in providing measurements that involve curves, making them the appropriate choice for this question.