Package Includes: 50 x Black Oxide Flat WasherFits: 7/16 Inch fasteners; Inside Diameter: 0.49 Inch; Outside Diameter: 0.9 Inch; Thickness: 0.06 InchMetal Washers: Made of high quality carbon steel. Black oxidation treatment on the surface to prevent rust.Suitable for household and commercial appliances, bolt and nut connections. Used to increase load-bearing capacity and to protect materials.