A square section spring washer designed to prevent the nut from loosening. Plated in Trivalent Chromium (Cr3) Zinc"Hole Dia. mm - M12Length mm - 18Width mm - 5Thickness mm - 3.0Finish - Zinc & Clear Cr3Material - Carbon Steel Timco Spring Washers - Zinc (Size M12 - 200 Pieces) in Silver Size: 1000mm x 1000mm