HISTORY OF TAPPING
THE HISTORY OF TAPS AND DIES
HISTORY OF TAPPING
A Tap is a tool to cut an internal screw thread.
A metal-working revolution occurred between 1775 and 1825 that changed the whole pattern of man's living and introduced the modern Machine Age.
Up until this period, the chief metal-working tools were the hammer, the cold chisel and the file.
Then came Watt and his steam engine which provided the power needed to run machinery, and Henry Maudslay with his screw-cutting lathe. Mumford calls this "one of the decisive pieces of standardization that made the modern machine possible".
For the first time it became possible to design and cut uniform, accurate screw threads.
The era of interchangeability and mass production was born. Eli Whitney was able to amaze the U.S. war department in 1799 by assembling 10 muskets from parts which were interchangeable.
All during the 19th Century the design and accuracy of metal-working tools were improved. The invention of the turret lathe about 1845 was an important milestone in manufacturing with metal.
The tap fast became a key tool in Manufacturing.
Its counterpart, the die for cutting external threads, went
through some major changes in design. Until 1872, external threads were chiefly
cut by "jamming" a rod into a threaded hole in a metal plate. Known as
"jamb plates", these early thread-cutting tools were crude and
inaccurate. In 1872 John J. Grant came to Greenfield, Massachusetts, with an
idea for a die which actually cut metal, the two-piece adjustable die. The
demand for this improved tool was so great that a major industry was born almost
Nearly all taps being made today are precise to a degree impossible 50 years ago. They must be so to meet the demands of a civilization which literally "hangs by a thread" in its millions of machines, in its automobiles, in its planes, and in the factories that produce the comforts and conveniences as well as the weapons of our age.
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