When surfaces slide relative to one another, there is a tendency for one material to transfer onto the counterface. This is adhesive wear, that in its most severe form, results in galling and possible seizure of the machine through of cold welding.

Adhesion is usually combated using dissimilar materials and harder surfaces. Sulzer Metco offers a wide variety of solutions using coating and diffusion techniques for specific applications. For highly loaded components, such as gears, plasma nitriding is an excellent, if not at times, the only solution.