Grade: YGH40 hardness: 240 Density :13.5-13.9 Uses: mainly used for the production of red die. Depends on the hardness of cemented carbide hardening phase content and grain size, that is the higher content of the hardening phase, the finer the grain, the greater the hardness. The toughness of the bonding metal carbide decision bonding metal content is higher, the bending strength. 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. United States in 1929 in the original composition of Schwarzkopf added a certain 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.