Back Home / Fasteners / Washers / LOCK WASHER INTERNAL ZINC #12 INTERNAL TOOTHED LOCK WASHER INTERNAL ZINC #12 INTERNAL TOOTHED SKU: ILW12 Categories: Fasteners, Washers A hardened circular washer with twisted prongs or teeth which extend inward from the inside edge of the washer. This style is preferred when finished appearance is crucial and the teeth must be hidden under the head of the screw Made from spring steel, zinc plated. Rockwell Hardness: C40-50. Inside Diameter: Min .221 Max .231 Outside Diameter: Min .394 Max .410 Thickness: Min .020 Max .027 Case Quantity: 100 Log In For Pricing