🔍 Key Concepts

• Role of graphite as a solid lubricant in machinery • How grease works in a bearing under pressure and motion • Difference between sealing, cooling, and lubricating/surface functions in compounds

💭 Think About

• Think about what makes graphite special: is it better known for blocking moisture, sealing gaps, cooling, or helping surfaces move smoothly? • In a bearing, what problem is the lubricant compound mainly trying to solve when metal rubs on metal? • Which option best matches a material that can still reduce friction even if the grease thins out or is squeezed away?

✅ Before You Answer

• Identify the primary known property of graphite in mechanical applications (lubricity vs. sealing vs. cooling). • Consider how graphite’s plate-like structure affects contact between two rubbing surfaces. • Eliminate any option that does not directly relate to reducing friction or improving sliding between surfaces.