Shims are versatile components that can play a role in various application scenarios. The materials used for making shims are diverse. In terms of metallic materials, there is steel, such as carbon steel and alloy steel, which have high strength and hardness and can withstand pressure, and are commonly used in mechanical connection parts. Copper (including brass, red copper, etc.) is soft in texture, has good thermal and electrical conductivity, and is ductile, and is suitable for connecting electrical equipment and some mechanical devices that require sealing and reduced wear. Aluminum and aluminum alloys are lightweight and corrosion-resistant, and are used in aerospace equipment and outdoor mechanical devices. In conclusion, shims can meet the assembly and operation requirements of different equipment by filling and adjusting gaps, etc.