Identify two common lubricating materials used in engineering machines. - Leaving Cert Engineering - Question (a) - 2013

1. Oil: A liquid lubricant commonly used for reducing friction in various machinery and engines. Oil can come in various forms, such as mineral oil or synthetic oil, tailored for specific applications to improve performance and efficiency.

2. Grease: This is a semisolid lubricant made by combining oil with a thickening agent. Grease is often used in situations where liquid lubricants might leak or evaporate, providing better adhesion and durability.

Both oil and grease are essential for maintaining the longevity and efficiency of engineering machines.