The engineer designing the machine will decide which is best for the application. This causes the shaft and gear to become locked together when rotating, thus transferring rotational force between the shaft and gear.Ī pulley or gear can fit onto a shaft via a straight bore or a tapered bore. The gear can then be fitted onto the shaft and the keyway on the gear will fit over the key, inserted in the shaft. Then and a piece, usually metal, called a key is inserted into the shaft keyway.

A notch called a keyway is cut on the inside of the gear along with another notch cut, longways, into the shaft. When a gear, or something similar, needs to fit onto a rod or shaft and transfer force, in the form of rotation, a key helps accomplish this. Keep reading for more about the different ways to use the keyway-cutting method. Keyway cutting helps bond a gear or pulley to a shaft. Whether it’s a car or a vacuum cleaner, most have rotating parts with a shaft fixed to a gear. Today, most modern machines are comprised of rotating gears and pulleys.