Chuck Mulcahy, a.ge 15, of Biloxi, Miss., for his question:
WHAT IS A MACHINE TOOL?
A machine tool is a piece of equipment used to shape metal. These important tools shape metal by cutting, shearing, hammering or squeezing. Machine tools do to metal what a carpenter's tools do to wood.
A machinist is a worker who operates a machine toot. He cuts, drills, planes and grinds or shapes metals with power driven machine tools.
Machine tools play an important part in the production of almost all metal products known to man. They make the working parts of telephones, television sets, radios and washing machines. Refrigerators could not work without the ability of machine tools to make the precise parts they need to operate. They are also essential to the manufacture of automobiles.
There are more than 400 kinds of machine tools, each designed to do a certain type of work. Each kind of tool comes in various sizes. Each size and type have many special attachments that make metalworking easier.
Machine tools can be classified into six major groups, according to the six basic operations in shaping metals: drilling and boring, which include reaming and tapping; turning; milling; planing, which includes shaping and broaching; grinding, which includes lapping and honing; and metal forming, which includes shearing, pressing and forging.
Metal forming machine tools are the giant successors to the tools used by blacksmiths. They include presses, shears, press brakes, drop hammers and forging machines.
New developments in machine tools include the electrical discharge method and the ultrasonic method. Both are useful in working with extremely hard metals.
West Germany ranks as the leading producer of machine tools in the world, followed by Russia and the United States. Other countries with large machine tool industries include France, Great Britain, Italy and Japan.
When James Watt began his experiments with the steam engine in 1763, he could not find anyone who could drill a perfect hole. As a result, his engines leaked steam until an Englishman named John Wilkinson invented the boring machine in 1774.
The planer, like the boring machine, was not developed until needed to make steam engines. Three Englishmen, Matthew Murray, Joseph Clement and Richard Murray, took part in its development between 1800 and 1825.
The principle of the lathe was known in ancient times. The idea probably originated with the potter's wheel. Hut until 1800, lathes were crude machines that could not be used to cut screw threads accurately. That year an English inventor named Henry Maudsisy came up with the first good screw cutting lathe.
Then in 1836, an assistant to Maudsiay named James Nasmyth invented the shaper as well as the steam hammer and other maiche tools.
In 1873, an American named C.M. Spencer developed a fully automatic lathe, often called an automatic screw machine.