The tungsten carbide contained in Tungsten carbide hole saws are compound composed of tungsten and carbon, with a molecular formula of WC and a molecular weight of 195.85.
Since 1893, German scientists have been using tungsten trioxide and carbon to heat to a certain temperature in an electric furnace to produce tungsten carbide. They tried to use its high melting point and high hardness to make wire drawing dies to replace diamond materials. However, tungsten carbide has never been used in industry due to its brittleness, easy fracture and low toughness. After about 1920, German scientists discovered through research that pure tungsten carbide no longer adapts to the drastic stress changes formed during the drawing process. Only by adding low melting point metal to WC, the blank can be manufactured without reducing the hardness, and the blank also has a certain degree of toughness. German scientists first proposed a powder metallurgy method in 1923, that is, tungsten carbide is mixed with a small amount of iron group metals (iron, nickel, cobalt), then pressed into a shape, and sintered in hydrogen above 1300°C to form a hardness alloy.
Tungsten carbide is a black hexagonal crystal with metallic luster and hardness similar to diamond. It is a good conductor of electricity and heat. Tungsten carbide is insoluble in water, hydrochloric acid and sulfuric acid, but easily soluble in a mixed acid of nitric acid and hydrofluoric acid. Pure tungsten carbide is easy to crack. If these metals (such as titanium and cobalt) are mixed in small amounts, the brittleness will be reduced. Tungsten carbide used as steel cutting tools is usually added with titanium carbide, tantalum carbide or their mixtures to improve the anti-knock ability. The chemical stability of tungsten carbide is suitable for the production of cemented carbide.