The material used to make the tool must have high high temperature hardness and wear resistance, necessary bending strength, impact toughness and chemical inertness, good processability (cutting, forging and heat treatment, etc.) and not easily deformed.
Generally, when the hardness of the material is high, the wear resistance is also high; when the bending strength is high, the impact toughness is also high. However, the higher the hardness of the material, the lower the bending strength and impact toughness. High-speed steel is still the most widely used tool material due to its high flexural strength and impact toughness, as well as good processability, followed by hard alloys.
Tool materials are roughly classified into the following categories: high speed steel, hard alloy, cermet, ceramic, polycrystalline cubic boron nitride, and polycrystalline diamond. What kind of tool is required to produce what kind of product.
For example, polycrystalline cubic boron nitride is suitable for cutting high hardness hardened steel and hard cast iron; polycrystalline diamond is suitable for cutting iron-free metals, and alloys, plastics and glass steel; carbon tool steel and alloy tool steel are now only Used as a tool for trowels, dies and taps.