Silicon Bronze hex nuts are made from an alloy of mostly copper and tin, containing a small amount of silicon. Dimensional specifications are governed by ASME B18.2.2 for finish nuts, and ASME B18.6.3 for the smaller diameter machine nuts. There are no grade markings on bronze hex nuts. Fasteners made from silicon bronze are ideal for naval construction and are popular in the marine industry, because they are resistant to salt water, electrically conductive and nonmagnetic. They are also commonly used in general construction, refineries, and the power and energy industry as well. Compared to brass fasteners, bronze is much harder and more resistant to corrosion.