What is Lubricant?
{{nosources|date=October 2013}} A '''lubricant''' is a [[substance]] used to reduce [[friction]] between [[Movement|moving]] surfaces. The property of reducing friction is known as ''lubricity'' (slipperiness). A good lubricant has the following characteristics: * Does not get affected by [[temperature]] or [[pressure]] at all * Does not [[Combustion|burn]] easily, and may also prevent [[rust]]ing * High [[viscosity]] (feels like a very thick liquid) * Does not [[Miscibility|mix]] with water The most often used lubricant is [[motor oil]], which is used in [[engine]]s of cars and motorcycles. Sometimes, chemicals are added to normal oil to give it special properties. A lubricant, like motor oil, can also help in reducing [[heat]]. Simply put, cooling depends on surface area in contact. So, if something normally has a small surface area, you can put that thing into a bigger pot, and put oil in the pot. This way, oil comes in contact with small surface area of the small object, and transfers that heat to the big surface area of the big vessel. As a rule, liquids can transfer heat better than [[gas]]es. In [[manufacturing]], sometimes oil is used to cool the item being made. This also helps in removing metal that was just chipped off. This chipped-off metal normally flows with the oil until it is [[filter]]ed. Then the oil is reused. The filtered metal chips are normally scrapped. Sometimes, lubricants are used for [[Hydraulics|hydraulic]] machines. A hydraulic machine uses the fact that the hydraulic oil cannot be [[Physical compression|compressed]], and performs a simple conversion – it works like a [[lever]]. Some common lubricants are: * Solid: [[graphite]] (used in lead pencil), * Semi-solid: [[Petroleum|grease]] * Liquid: Oil of various grades and types Oils can cause [[pollution]], especially [[water pollution]], if released into the open. [[Category:Oils]] [[Category:Materials]]