Flat Washer,made of Stainless Steel,with Round/Square/Curved Shape and Zinc/Nickel Finish. Size: M3-M76Material: steel,stainless steel,low carbon steel,alloy steel,brass or brass alloy,aluminumor aluminum alloyShape: round,square,curved,taper,cup,bowlHeat Treatment: passivated,carburized and moreSurface Finishing: zinc-plated,black anodize,nickel,chrome-plated and more FLAT WASHER