These metallized screws are made of 100% stainless steel 410, one of the highest forms of corrosion resistant steel, and are thus longer than the rest of today's market. SELF-WINNING: Our hardware is very powerful and is suitable for indoor as well as for outdoor use. Stainless steel is better than ordinary steel and offers excellent rust resistance when used in water. LARGE STORAGE: The dispenser hardware is great for use in sheet metal and moisture environments. The Bolt Dropper Hardware is the highest quality available on the market and we are 100%. They are robust, corrosion resistant and support all your projects.