Taiwan Chun Bao cobalt tungsten steel WF15: 10 Size: 0.7 Hardness: 91.8 Specific Gravity: 14.08 Flexural strength: 370 Usage: drilling, milling cutters, reamers and other cutting tools, titanium, cast iron, stainless steel. In 1923, the German Shileteer tungsten carbide powder added to the 10% to 20% cobalt binder to do, the invention of a new tungsten carbide and cobalt alloy, hardness only to diamond, which is the world's artificial into a first cemented carbide. With this cutting tool made of steel alloy, the blade will wear out quickly, even edge crack. In 1929, the United States Schwarzkopf component added to the original amount of tungsten carbide and titanium carbide compound, improves the performance of cutting tool steel. This is yet another achievement in the history of carbide. Carbide with high hardness, wear resistance, strength and toughness, heat resistance, corrosion resistance and a series of excellent performance, especially its high hardness and wear resistance, even at 500 ℃ temperature also remained unchanged , at 1000 ℃ still very high hardness. Carbide is widely used as a tool material, such as turning, milling, planer, drill, boring tools, etc., for cutting cast iron, nonferrous metals, plastics, chemical fiber, graphite, glass, stone and ordinary steel can also be used to cut heat-resistant steel, stainless steel, high manganese steel, tool steel and other difficult to machine materials. Carbide cutting tools are now new carbon steel equal number of times.