Large gear components can be offered in many applications such as in marine@ wind power@ steel rolling mills@ power plants@ transportation@ railroad@ aircraft@ cement crushers@ mining and oil industry applications. There are three important surface hardening methods used to improve and expand the technical use of gear components. Design and material engineers must decide which hardening method to use. Case hardening is normally the first choice because of the highest load capacity. But@ case hardening also poses challenges that must be acknowledged. Therefore@ it is good to know that there are three options for very large components.