Back to basics first, some of background info Penetration 針入度 Penetration 針入度 係指標準圓錐體在5秒鐘內，沉入潤滑脂 dN value ( more applicable for oil) dN would equate to [½] x [OD+ID] x rpm average diameter is 60mm rpm is 0.1 so dN is 6 nominal components of lubricating grease: Dropping point (滴點) is generally used for greases, and indicates heat resistance of a grease up to a temperature. At this point, greases tends to start dropping down a vertical surface. Grease does not remain much useful beyond this temperature. The formula for kinematic viscosity is 1 centistoke (cSt) equals 1 millimeter squared per second (mm2/s). This is a rate of flow. It is the time it takes to have a known amount of fluid flow a given distance. There is no external force pushing the fluid. Only gravity is used. This means the fluid’s weight or density helps it to flow. Kinematic viscosity incorporates fluid density as part of its measurement. Types of grease : Valvoline 101 pros and cons o...