How are greases classified in terms of their properties?

Greases are classified primarily by their mobility and oil content because these properties significantly influence their performance in various applications. Mobility refers to how easily a grease can flow and spread, which is crucial for its effectiveness in lubricating surfaces under different conditions. Higher mobility greases tend to be used in applications that require easier spreading and lower resistance. The oil content is also essential, as it determines the grease's ability to maintain a lubricating film under pressure and temperature, along with its overall performance in reducing friction and wear.

The other classifications such as temperature stability, viscosity, or physical characteristics like color and texture, while important, do not encompass the broader aspects of grease functionality as comprehensively as mobility and oil content do. Temperature stability is important for determining how well a grease can perform under extreme heat or cold, but it does not take into account how the grease will behave in terms of flow. Viscosity is a critical factor, but it is only one aspect of grease performance. Similarly, color and texture may provide information about the formulation of the grease but do not relate directly to its efficiency in lubrication tasks. Therefore, focusing on mobility and oil content gives a better understanding of how greases operate in practical applications.