Whether for home, farm, builder or industrial customers, National has all the right hardware in the sizes and finishes you need. With over a century of service National is committed to maintaining the highest level of product quality, innovation and manufacturing technology. Providing a reliable barrier against unauthorized entries. Barrel bolts add additional security and are made in standard, heavy duty or extra heavy duty versions for indoor and outdoor applications. A proprietary weather guard zinc coating is three times more corrosion resistant compared to the competition. This galvanized finish offers corrosion resistance for products used where corrosive elements, such as salt air, are present.