Outside Micrometer Caliper

A precision measuring instrument with a micrometer screw attachment used for making exact external linear measurements of thickness, outside diameters, or distances over two parallel planes. It consists of a u-frame and a micrometer, the spindle of which is aligned with an opposite anvil. It may incldue a dial indicator, digital display, and/or a push-button mechanism which activates a retractable anvil to assure uniformity of contact pressure, and permits use as a visual comparator. Graduations may be in inches and/or millimeters.