Washers serve the purpose of evenly distributing the pressure from a fastener head, mitigating the risk of gradual loosening while ensuring the fastener maintains contact with the surface to prevent material damage. The most common type, flat washers, feature entirely level surfaces that distribute the force exerted by a nut or bolt. Lock washers, on the other hand, firmly secure nuts and bolts in place by gripping into fastener heads and materials, resulting in tighter assemblies compared to flat washers. Meanwhile, sealing and cushioning washers create an airtight seal between fasteners and surfaces, preventing fluid leakage. Countersunk washers, with their recessed and bowl-shaped design, enable screws to sit flush with the work surface, offering a polished and smooth appearance.