Hot-dip galvanized nuts are corrosion-resistant nuts made of carbon steel that have undergone hot-dip galvanizing. These nuts are typically used with hot-dip galvanized bolts for connections in steel structures exposed to wind and rain for extended periods, such as outdoor transmission towers, communication base stations, streetlight poles, bridge railings, and photovoltaic supports. While ordinary nuts rust after a few months outdoors, hot-dip galvanized nuts, thanks to their thick zinc coating, can remain rust-free for years, even decades, in humid and salt spray environments. Because hot-dip galvanizing increases the nut's thickness, the thread clearance of hot-dip galvanized nuts is pre-enlarged during manufacturing to ensure a smooth fit with hot-dip galvanized bolts, preventing them from getting stuck or jamming.
Hot-dip galvanized steel structure bolts are indispensable anti-corrosion fasteners in outdoor steel structure buildings, transmission towers, communication towers, railway catenary supports, and photovoltaic brackets. Compared with ordinary steel structure bolts, hot-dip galvanized steel structure bolts significantly improve weather resistance while retaining high preload and anti-slip performance. These hot-dip galvanized steel structure bolts are typically used with large hexagonal nuts and washers to form connection pairs, installed using the torque method or angle method, suitable for friction or bearing connections. In uncoated weather-resistant steel structures, hot-dip galvanized steel structure bolts can also serve as a supplementary anti-corrosion measure for bolted connections.
Dacromet Hex Bolts are a new type of environmentally friendly, corrosion-resistant fastener made by coating high-strength hexagonal bolts with a Dacromet chromium-free zinc-aluminum coating. These Dacromet Hex Bolts are formed by dipping or spraying flake zinc powder, aluminum powder, and a special binder, followed by high-temperature sintering to create a uniform silver-gray coating. Compared to traditional hot-dip galvanizing or electro-galvanizing, Dacromet Hex Bolts offer superior resistance to hydrogen embrittlement, high temperatures, and salt spray. They are widely used in automotive engine peripheral components, wind turbine generators, rail transit braking systems, and marine engineering equipment. For high-strength bolt connections of grade 8.8 and above that require high corrosion resistance and are sensitive to hydrogen embrittlement, Dacromet Hex Bolts have become the preferred alternative to electro-galvanizing and some hot-dip galvanizing methods.
Dacromet wheel bolts are highly corrosion-resistant fasteners specifically designed for wheel hub connections in passenger cars, commercial vehicles, and high-performance vehicles. These Dacromet wheel bolts are developed for conditions where wheel bolts bear high alternating loads, are extremely sensitive to hydrogen embrittlement, and are exposed to road salt spray and muddy environments. Traditional electroplated galvanized wheel bolts are at risk of hydrogen embrittlement fracture even at high strength grades, while Dacromet wheel bolts completely eliminate this risk through a hydrogen-free coating process. Furthermore, Dacromet wheel bolts have a uniform and aesthetically pleasing silver-gray appearance, excellent coating wear resistance, and maintain good rust prevention even after repeated disassembly and reassembly. Currently, Dacromet wheel bolts are adopted as original equipment by numerous joint venture and domestic brand automakers.
Dacromet double-ended bolts are corrosion-resistant fastening solutions that apply Dacromet coating technology to double-ended bolts. These Dacromet double-ended bolts are widely used in high-temperature and high-corrosion environments such as turbocharger connections, high-pressure common rail fuel systems, exhaust manifold mounting, and chemical valve flanges. Ordinary surface-treated double-ended bolts are prone to rusting and seizing under high temperatures and corrosive media, leading to difficult disassembly. Dacromet double-ended bolts, with their high-temperature resistance, corrosion resistance, and anti-seizing properties, can maintain smooth assembly and disassembly of the threaded joints for a long time. Furthermore, the threads at both ends and the smooth shank of Dacromet double-ended bolts receive a uniform coating, eliminating the insufficient coverage at the thread root common in electroplating, making them particularly suitable for equipment requiring regular maintenance.
Dacromet steel structure bolts are high-performance fasteners used in outdoor steel structures, bridges, towers, and photovoltaic power plants, where high corrosion resistance is required. While retaining the high preload and anti-slip properties of traditional steel structure bolts, these bolts utilize a Dacromet coating to address issues such as hydrogen embrittlement, unstable torque coefficient, and rough appearance inherent in traditional hot-dip galvanized steel structure bolts. In cross-sea bridges, coastal power plants, chemical plant steel structures, and wind turbine towers in high-altitude and cold regions, Dacromet steel structure bolts resist chloride ion corrosion, freeze-thaw cycles, and industrial atmospheric erosion. Notably, the torsion-shear type Dacromet steel structure bolts, when combined with the Dacromet coating, exhibit stable fracture torque at the sputter head, and the coating does not peel off, making construction quality easier to ensure.