Glossary

Marine hardware refers to fasteners, fittings, components, and structural accessories designed for use on boats, docks, ships, marinas, offshore equipment, and other environments exposed to water, salt, humidity, UV, vibration, and constant weathering. In simple terms, it is hardware built to survive around water, especially saltwater, where ordinary steel hardware would corrode quickly.

Marine hardware includes a wide range of products such as bolts, screws, nuts, washers, shackles, cleats, eye bolts, turnbuckles, hinges, latches, hooks, rings, rail fittings, chain, wire-rope fittings, dock hardware, brackets, clamps, and mounting hardware. The common thread is that these parts must resist corrosion while also handling mechanical loads, movement, shock, and long-term outdoor exposure.

Material selection is one of the most important parts of marine hardware. Stainless steel, especially 316 stainless steel, is commonly used because it contains molybdenum, which improves resistance to chloride attack from saltwater. 304 stainless steel may be acceptable in freshwater or mild outdoor environments, but 316 is generally preferred for coastal, marine, and salt-spray conditions. Other marine hardware materials may include silicon bronze, phosphor bronze, naval brass, aluminum, galvanized steel, and specialized coated steels, depending on the application.

Corrosion resistance in marine service is not only about “not rusting.” Marine hardware must resist several types of attack, including pitting corrosion, crevice corrosion, galvanic corrosion, and general atmospheric corrosion. For example, stainless steel can perform well when exposed to oxygen, but it may suffer crevice corrosion in tight, wet, oxygen-starved areas. Galvanic corrosion can also occur when dissimilar metals are connected in the presence of an electrolyte, such as saltwater.

In fastener terms, marine hardware often needs careful matching of materials. A stainless bolt installed through aluminum, bronze, or galvanized steel can create corrosion issues if the joint stays wet and electrically conductive. Designers may use isolation washers, sealants, coatings, bedding compounds, compatible alloys, or sacrificial anodes to reduce galvanic corrosion risk.

Marine hardware also has to handle movement. Boats, docks, and marine structures are constantly exposed to vibration, wave action, wind loading, impact, thermal cycling, and repeated wet-dry cycles. That means hardware often needs good fatigue resistance, secure locking features, proper preload, and reliable load capacity. A cleat, shackle, turnbuckle, or eye bolt is not just “holding something”; it may be carrying dynamic loads that change constantly.