Gear cutting machines are machine tools used for the production of gears. Gears are special shapes placed on two interacting parts to connect them together and allow rotational transmission of force or motion. Gear cutting machines can include broaching and milling machines, grinding machines, threading machines, and planing machines. These machines are used to create the splines on the parts that are responsible for transmitting power or motion. The splines can have different shapes, such as straight, spiral, conical or circular splines. The gear cutting machines must be very precise and accurate in order to ensure high quality of the gears and therefore high quality of transmission of force or motion.