Spring washers, also known as disc springs or Belleville washers, are a type of washer designed to provide flexibility and prevent loosening in various applications. These washers are typically made of spring steel and feature a conical shape that allows them to compress and expand under load, providing a cushioning effect and maintaining tension in bolted joints. Spring washers are commonly used in automotive, aerospace, and industrial settings to absorb vibrations, compensate for thermal expansion, and prevent fasteners from coming loose due to constant movement or heavy loads.