🔍 Key Concepts

• Lubricating oil viscosity and how it changes with temperature • Difference between oil properties that affect flow and film strength vs. safety/handling (like flash point) • What property most directly affects the formation of a protective oil film between moving parts under load

💭 Think About

• Ask which property determines how thick or thin the oil film is at the machinery’s normal operating temperature • Consider which property will most affect whether metal surfaces keep a continuous oil film instead of touching each other • Think about which property you would select first when choosing an oil grade for a specific engine or gearbox

✅ Before You Answer

• Identify the property that is specified by numbers like SAE grades or ISO grades for oils • Distinguish between properties related to combustion/ignition risk and those related to mechanical protection • Verify which property most directly controls oil flow and film thickness inside bearings at operating temperature