Most knives are machine-used, but there are also hand-used ones. Since the tools used in mechanical manufacturing are basically used to cut metal materials, the term "tool" is generally understood as a metal cutting tool. Tools used for cutting wood are called woodworking tools.
The development of knives occupies an important position in the history of human progress. As early as the 28th to the 20th century BC, copper tools such as brass cones and red copper cones, drills, and knives appeared in China. In the late Warring States period (third century BC), copper knives were made due to the mastery of carburizing technology. The drill bits and saws at that time have some similarities with modern flat drills and saws.
However, the rapid development of knives came with the development of steam engines and other machines in the late 18th century. In 1783, René of France first produced milling cutters. In 1792, Mozley of England produced taps and dies. The earliest documentary record of the invention of twist drill was in 1822, but it was not produced as a commodity until 1864.
The tools at that time were made of solid high-carbon tool steel, and the allowable cutting speed was about 5 m/min. In 1868, the British Musche made alloy tool steel containing tungsten. In 1898, Taylor and. White invented high-speed steel. In 1923, Schroeter of Germany invented cemented carbide.
When using alloy tool steel, the cutting speed of the tool is increased to about 8 m/min. When using high-speed steel, it is increased by more than two times. When using cemented carbide, it is more than two times higher than that of high-speed steel. The surface quality and dimensional accuracy of the workpiece are also greatly improved.
Because high-speed steel and cemented carbide are more expensive, the tool has welding and mechanical clamping structure. Between 1949 and 1950, the United States began to use indexable inserts on turning tools, and soon used them on milling cutters and other tools. In 1938, the German Degussa company obtained a patent on ceramic knives. In 1972, General Electric Company produced polycrystalline synthetic diamond and polycrystalline cubic boron nitride blades. These non-metallic tool materials enable the tool to cut at a higher speed.
In 1969, the Swedish Sandvik Steel Plant obtained a patent for the production of titanium carbide coated carbide blades by chemical vapor deposition. In 1972, Bangsar and Lagolan in the United States developed a physical vapor deposition method to coat a hard layer of titanium carbide or titanium nitride on the surface of cemented carbide or high-speed steel tools. The surface coating method combines the high strength and toughness of the base material with the high hardness and wear resistance of the surface layer, so that this composite material has better cutting performance.