Washers serve to distribute pressure by increasing the contact area, thereby preventing the surfaces of connected components from being crushed or undergoing plastic deformation. They also protect the bearing surfaces of bolt heads or nuts, guarding against damage caused by localized high-pressure concentrations. Washers fill minute surface irregularities on the mating faces, ensuring uniform pressure distribution and facilitating the more efficient transmission of the bolt's axial force to the connected components. In connections involving angular misalignment, pairs of tapered washers can be utilized to compensate for the deviation, ensuring the bolt is installed perpendicular to the load axis and preventing it from being subjected to additional bending stresses. Furthermore, washers protect the anti-corrosion coatings on the surfaces of connecting plates, preventing corrosion that might otherwise result from coating damage caused by localized high pressure.
In automotive assembly and maintenance, washers help prevent fasteners from loosening under vibration and dynamic loads, thereby enhancing the stability of the connection. They also allow for the precise adjustment of gaps between components, resulting in more accurate assembly, and serve to isolate the fastener from the connected component, thereby reducing the potential for electrochemical corrosion. In high-strength bolted connections, it is imperative to use washers manufactured from high-strength steel that have undergone hardening treatments; this ensures their strength and hardness are sufficient to withstand high pre-tension loads without being crushed or deformed. It is strictly prohibited to arbitrarily increase the number of washers-particularly by stacking multiple thin washers-as this can compromise the stability of the connection. Washers must be selected to precisely match the specifications and performance grade of the corresponding bolts; the use of washers with oversized inner diameters, undersized outer diameters, incompatible materials, or those that are damaged is strictly forbidden.
