What kind of caliper is used for locating the center of a shaft?

The hermaphrodite caliper, also known as a center or saddle caliper, is specifically designed for locating the center of a shaft. Its unique shape features a pair of pointed jaws which can be used to make precise measurements and mark the centerline on cylindrical objects. By aligning the caliper to the diameter of the shaft and marking the points where the caliper intersects with the shaft, a technician can easily determine the center.

While the other tools have their own specific applications, they do not suit this particular task as effectively. The vernier caliper is used for measuring internal and external dimensions with high precision, but it is not specifically designed for centering shafts. Digital calipers provide easy-to-read measurements but do not have the specialized structure needed for locating a shaft's center. Micrometers are more suited for measuring small dimensions with great accuracy, but they also lack the shape and functionality required to find the center of a shaft. Thus, the hermaphrodite caliper stands out as the most appropriate tool for this specific measurement task.