Hydraulic is by far the simplest method to transmit energy to do work. It is considerably more precise in controlling energy and exhibits a broader adjustability range than either electrical or mechanical methods.
Mineral oil hydraulic fluids as a class are the most common hydraulic fluids used in the fluid power industry.
Grease is a semi-fluid to solid mixture of a fluid lubricant, a thickener, and additives. The fluid lubricant that performs the actual lubrication can be petroleum (mineral) oil, synthetic oil, or vegetable oil. The thickener gives grease its characteristic consistency and is sometimes thought of as a “three-dimensional fibrous network” or “sponge” that holds the oil in place.
Rolling of metal is a process by which the thickness of the metal is reduced to the desired level by means of rotating rolls in a mill.