Special washers are a staple category at Engineered Source and we supply our customer base with a wide range of types, sizes, and materials.  This is a special belleville washer made in the United States using SAE 1060 spring steel material and heat treated to 42-48 HRC.  It measures .475 on the inside dimension, .848 on the outside dimension, and .060 in thickness.  20 degree offset angle is used per customer's print specifications.