Product Description Hillman Flat Washer Stainless Steel - Stainless steel flat washer is used to spread the load of a screwed fastening or when the hole is a larger diameter than the fixing nut. - Type: Flat, Slot Size: 3/8", Inside Diameter: 7/16", Outside Diameter: 1", Thickness: 0.064"/0.104", Package Size: 100 pcs, Material: Stainless Steel, Pkg Qty: 100, Package Type: Box From the Manufacturer 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.