The Hillman Group USS Flat Washers, 1/2" Diameter, 9/16” Drive Size, Steel with Zinc Finish, 50 Pack
Used in applications with nuts and bolts. The flat washer provides a greater bearing surface which helps prevent a nut or bolt head from tearing through the material. Flat washers are commonly used in decks and fence building. The called out size is the inner diameter of the washer.