What is lubricating oil?

Lubricating oil is a fluid typically used to reduce frictional forces between two surfaces. The surface of the object with the higher coefficient of friction is usually treated with some form of lubricant, such as grease or wax or oil, which creates lower force on that surface and inhibits wear over time while also reducing heat.

When it cools off enough to thicken slightly and forms an even more effective shield from moisture and dirt particles that can be abrasive if they work their way into machinery bearings at top speeds.

Originally published on quora @sequoia-global