It has the characteristics of high hardness, high compressive strength, good thermal conductivity and wear resistance, and can achieve high machining accuracy and efficiency in high-speed cutting. The above characteristics of diamond cutting tools are determined by the state of diamond crystals. In diamond crystals, the four valence electrons of carbon atoms are bonded in a tetrahedral structure, with each carbon atom being connected to four adjacent atoms

Atoms form covalent bonds, which in turn form diamond structures with strong binding and directionality, giving diamond extremely high hardness. Due to the fact that the structure of polycrystalline diamond (PCD) is a sintered body of fine grain diamond with different orientations, even with the addition of binders, its hardness and wear resistance are still lower than those of single crystal diamond. However, due to the isotropic nature of PCD sintered bodies, they are not easily cracked along a single cleavage plane.