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. Strap punched for 5/16 inch (6 or 8 inch sizes) or 3/8 inch ((1, 12, 14, 16, 18, 2 and 24 inch sizes) bolts. WeatherGuard - When subjected to 312 hours of salt fog spray testing (BHMA A138.18), zinc plated hardware showed severe corrosion while hardware with WeatherGuard protection withstood these harsh conditions with very little deterioration.