Hex washer head, self-tapping screws are used for sheet metal to sheet metal fastening. These screws come with features which help them in tackling the constraints of metal to metal fastening. The screws are heat treated to increase their strength and holding abilities exponentially. It is available in stainless steel, carbon steel, and alloy steel to bear more wear and tear while also making it more corrosion resistant. Since these screws are self-tapping, there is no need to drill a pilot hole before using them.