Back Home / Fasteners / Washers / FLAT WASHER USS ZINC 1/2″ THRU HARDENED FLAT WASHER USS ZINC 1/2″ THRU HARDENED SKU: 8FW50 Categories: Fasteners, Washers Used to improve stress distribution, and to span large holes. USS PATTERN. Made from heat treated thru-hardened steel, zinc yellow. Outside Diameter: 1-3/8″ Inside Diameter: 9/16″ Case Quantity: 100 Log In For Pricing