No substance has been as important as metal in the story of man's control of his environment. Metals form the backbone of a nation and the entire economy of a nation depends on the metals it produces.Casting is one of the oldest manufacturing methods known to humankind and a very direct method of producing metal parts. In this process molten metal is poured into a mold that matches the final dimensions of the finished product. castings have allowed us to build equipment to feed our people, fight for democracy, and build infrastructure and manufacture cars, trains and airplanes. In general, castings have beenand will continue to bethe key ingredient in the recipe for a better way of life. While all metals can be cast, the most predominant are iron, aluminum, steel and copper-base alloys ranging in weight from less than an ounce to single parts weighing several hundred tons. The discovery of various metals has been shown in the timeline below.

The ancient expertise in casting resided among several cultures the Mesopotamians, the Egyptians, the han dynasty and the Indians.

MESOPOTAMIAN CIV.Mesopotamia is generally accepted as the birthplace of castings. Gold was the first metal to be discovered. Early men hammered ornaments out of gold nuggets that they found. Copper was the next metal to be put to use by mankind. Man found that copper hardened on being hammered and thus was used to make weapons. It was then (somewhere around 4500 BC) that metal casting was discovered when a copper nugget accidently fell into a campfire and was reshaped on solidification. The oldest casting in existence is believed to be a copper frog cast in Mesopotamia probably around 3200 BC.---------------------diagram---------------------INDUS VALLEY CIV.Progress in casting necessarily was slow. Meanwhile, excavations in India show that by 3000 BC, people were casting copper tools and weapons in closed molds. Copper was native to India, mined from the Khetri region of Rajasthan beginning in the 3rd-2nd millennium BC. Evidence exists that there were 16 copper furnaces in the Indus Valley.During the Indus valley civilization from pure copper, man moved to bronze castings when he learned, sometime around 3000 BC and again perhaps by accident, that the addition of tin to molten copper produced a much more useful material. Bronze was harder than copper and could be hardened more easily and was thus used to make weapons.

EGYPTIANS AND THE HAN DYNASTYInvestment casting is also known as lost wax casting. It traces back to the egyptians and Chinese previously discussed that used this method to create pieces of jewelry and delicate Features of other castings.Egypt, due to its close proximity and collaboration with Mesopotamia, was not far behind in casting metals. Egypt began working with bronze around 2800 BC, only a few hundred years after Mesopotamia first invented the process. The Egyptians produced statues from bronze.

China got a comparatively late start in the development of casting. Chinas Bronze Age did not begin until 2000 BC. However, despite the late start, China quickly learned the processes being used by the Mesopotamians and Egyptians, and began inventing improvements. The first production-of iron castings usually is attributed to the Chinese at a time shortly after 1000 BC, but certainly by the 6th century AD i.e. during the han dynasty.Since iron does not occur on earth in native form and could hardly have been smelted 6000 years ago, its origin has been attributed to meteorites in which it is found unoxidized. A summary of metal casting with respect to the various civilizations has been shown below.

Developments in metal casting came swiftly in the I4th and 15th centuries. Subsequently blast furnaces and sand molding techniques came up. Moreover steel was discovered. All the above discussion can be precisely understood by the timeline given below.