A caliper, also known as a sliding gauge, is a precision measuring tool used to take internal and external measurements as well as depth and step measurements of objects. It consists of a linear measuring rod mounted in a holder or handle that allows for the movement of the measuring rod. On one side of the measuring rod is a narrow, flat steel plate known as the measuring jaw or measuring blade. The measuring jaws can be configured to be flat or curved to allow for different measurements.
A caliper can be calibrated in metric or imperial units, and the reading of the measurements is usually done through a scale on the caliper or through an electronic display. The measuring range of a caliper may vary depending on the model and size, but typically it can make measurements in the range of a few millimeters to several centimeters.
The caliper is commonly used in manufacturing and mechanical engineering, but also in many other fields such as woodworking, metalworking, electronics, medicine, and science. Some models have additional functions, such as measuring internal bores with special measuring jaws or measuring depths with an attached probe.
Overall, a caliper is a versatile precision tool that allows the user to make accurate measurements necessary for a variety of applications.