تويت
Milling is a process of producing flat and complex shapes with the use of multi-tooth cutting tool, which is called a milling cutter and the cutting edges are called teeth. Unlike lathes, which have been known for thousands of years, milling machines are less than two hundred years old. Because they require much more power than hand-driven lathes, their introduction had to wait for the invention of industrial water and steam power. Also, all their mechanical components had to first be made available, such as accurately fitted slides, large castings to resist cutting forces, calibrated leadscrews, and hardened steel cutting tools. Eli Whitney is credited with inventing the first milling machine about 1818, but the knee-and-column support arrangement of the universal milling machine of Joseph A. Brown (later of Brown and Sharpe) dates from 1862 and marks an important step in the machine ’ s development. During the last half of the nineteenth Century, milling machines gradually replaced shapers and planers which have lathe-type, single-point tool bits that move over the work in a straight line and scrape off metal one stroke at a time. Milling machines, with their continuous cutting action, not only remove metal faster than shapers and planers, they perform additional operations like cutting helices for gears and twist drills. Today, milling machines greatly outnumber shaping and planing machines. Americans in New England and later the midwest continuously added features leading to the modern milling machine
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