Used 3 points - inside micrometer

The three-point internal micrometer is a measuring tool used to measure internal dimensions such as bores, cylinders or bushings. It consists of a measuring spindle, which is pressed into the opening to be measured by turning a ratchet, and three movable measuring pins, which are arranged uniformly at a 120-degree angle around the measuring spindle. The measuring pins move independently of each other and conform to the contour of the opening being measured to ensure accurate measurement. Three-point internal micrometers usually have an analog display and can take measurements in various units such as millimeters or inches. They are available in a variety of sizes and measuring ranges and are used in metalworking, engineering and other industries where accurate measurements of internal dimensions are required. Some models also have a digital display for faster and more accurate measurements.