Flat washers are usually thin parts of various shapes, used to prevent leakage, reduce friction, prevent loosening, separation or disperse pressure. Many mechanical structures or installations have such parts, used to perform various similar functions. Due to the process and material limitations of threaded fasteners, the bearing surface of fasteners such as bolts is not large, so washers are used to reduce the compressive stress of the pressure-bearing surface and protect the surface of the connected parts.
