External versus internal gearsExternal gears are gears with teeth formed on the outer surface of a cylinder or cone. In contrast, an internal gear is a gear with teeth formed on the inner surface of a cylinder or cone. As with bevel gears, internal gears are gears with pitch angles greater than 90 d

In the field of mechanical engineering, precision measurement of gears and other parts is often required. A gear measuring instrument is an ideal tool for measuring gears. It can realize the partial measurement of gear inspection, and the whole process is completed on a single machine.