The most common gear-cutting processes include hobbing, broaching, milling, and grinding. Rotary broaching requires two tooling components&colon; a tool holder and a broach. Broaching was originally developed for machining internal keyways. Linear broaches are used in a broaching machine, which is also sometimes shortened to "broach". Two machining operations, milling and broaching can be employed to form cut gear teeth. Other operations falling into miscellaneous categories include shaping, planing, boring, broaching and sawing. "Modular" broaches are commonly used for large internal broaching applications. Other operations such as broaching work particularly well for cutting teeth on the inside. This type of broaching holds closer tolerances than if the two cuts were done independently. In a seaway or surf therefore, the cutter was more prone to broaching. Vertical broaching machines rarely have a stroke longer than . Most surface broaching is done on a vertical machine. Continuous style machines are similar to the surface style machines except adapted for internal broaching. There are two main types of broaching&colon; "linear" and "rotary". Square-rigged sails are also less prone to broaching when running than Bermuda rigs.