Back Home / Fasteners / Washers / FLAT WASHER USS BLACK #10 FLAT WASHER USS BLACK #10 SKU: XSFW10-2 Categories: Fasteners, Washers Used to improve stress distribution, and to span large holes. SAE PATTERN. Made from low carbon steel, black oxide finish. Outside Diameter: 1/2″ Inside Diameter: 7/32″ Case Quantity: 100 Log In For Pricing