Solid Lubricants.

The use of lubricants probably dates back to the invention of the wheel. Since this early beginning, lubrication and the production of lubricating media have grown to be one of the largest industries in the world, yet from one-third to one-half of all the energy produced still is lost to friction. Until the early 1800s, animal fats and oils were the primary lubricant materials. Since the first oil well was drilled in Titusville, Pa., in 1859, the technology of lubrication has advanced rapidly. During the mid-1930s new materials developed to improve petroleum oils were first marketed. These materials, called additives, were used to increase the load carrying ability, lubricity, corrosion protection, and thermal oxidative stability of oils.