This flat washer provides a larger circular bearing surface which helps prevent a nut or bolt head from pulling through the material. It is round with a hole in the center and can also be used as a spacer. Flat washers are commonly used in any application using a bolt where 2 pieces are being drawn together. The package size designates the inner diameter of the washer. Used in applications with nuts and bolts of any kind as well as screw products. Available in various materials and finishes.