Grade: P40 Hardness: 90.5 Density: 13.10 bending strength: 2200 Purpose: high impact toughness, suitable for steel roughing. Basic knowledge of manufacturing machining carbide material must have high temperature hardness and wear resistance, the necessary bending strength, impact toughness and chemical inertness, good process (machining, forging and heat treatment, etc.), is not easy deformation. Usually when high hardness, high wear resistance; flexural strength, impact toughness is also high. However, the higher the hardness, flexural strength and toughness lower. High-speed steel for high flexural strength and impact toughness, and good processability, it is still the most widely used material, followed by carbide. Polycrystalline cubic boron nitride for cutting high hardness of hardened steel and hard cast iron, etc.; polycrystalline diamond for cutting non-ferrous metals and alloys, plastics and glass and steel; carbon tool steel and alloy tool steel now only for rasp, die and tap tool.