Also known as heavy hex nuts, these nuts are about 10% wider and taller than standard hex nuts and distribute the load over a large area. Grade 2H nuts are comparable in strength to Grade 9 bolts. They're about 20% stronger than high-strength steel nuts and are used in heavy machinery, such as earth-moving equipment.Hot-dipped galvanized steel nuts have a thick coating for better corrosion resistance than zinc-plated steel nuts. They must be used with other hot-dipped galvanized fasteners.