The cutting of gears is a specialist process, which can be achieved through a variety of machining methods.
Broaching is often used to manufacture different designs of gear, which involves the use of a broach tool to remove material as required.
However, the most common method of gear cutting is hobbing, especially within the production of helical and spur gear designs. Using a hob - a cutting tool with design variants depending on the gear type - the teeth or splines are cut into the gear accordingly. This process is fully-automated through the use of a hobbing machine, which often cater for both small and extremely large gear designs.