Vertical mills are commonly used for raw material and cement grinding. In terms of lubrication, the most critical parts of vertical mills are the bearings of the grinding rollers and the separator bearings and the gear box. The bearings of the grinding rollers are exposed to extremely high vibrations, elevated temperatures and the dust loaded environment in the grinding chamber. The Gearmaster pgp 680 and 1000 are developed for the lubrication of such highly loaded bearings. They are based on a fully synthetic oil, ensuring thickest lubrication films under extreme temperatures and loads.