Diamond is the hardest material on Earth, and due to its exceptional hardness, wear resistance, thermal conductivity, and chemical stability, it is an indispensable material for machining difficult-to-cut materials and for high-precision machining in manufacturing. It enables highly efficient and high-quality processing of materials that are difficult to machine with other tools, such as cemented carbides, ceramics, glass, composite materials, and semiconductor materials. Representative machining methods include grinding and polishing using grinding wheels and lapping with diamond abrasives, and high-precision cutting using PCD (polycrystalline diamond) and MCD (monocrystalline diamond) tools. This allows for high-precision shaping and mirror finishing, demonstrating its value in a wide range of fields such as semiconductors, optics, medical devices, and automotive parts.