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. Repair and replacement hardware for most windows on the market. 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. Repair and replacement hardware for most windows on the market.