Belleville Washers (also called Conical Washers or Belleville Springs) are designed to act as cone-shaped springs, and are often used to pre-load a fastener. Belleville Washers are intended to be flexible, and because of their conical shape, Belleville Washers create near-perfect concentric force dispersal.
Conical Belleville Washers are highly versatile, and can be installed in different positions for different effects. Two Belleville Washers installed facing the same direction will create a more rigid pre-load structure, whereas two washers facing in opposite directions will create a more flexible spring. Multiple Belleville Washers can be used in series to create very precise deflection forces, increasing or decreasing the force dependent on the direction of each washer.