Glossary

Naval brass is a copper-zinc-tin alloy designed for good strength, corrosion resistance, and serviceability in marine and industrial environments. It is a type of brass, but unlike ordinary copper-zinc brass, naval brass contains a small amount of tin, which improves resistance to corrosion in seawater and helps reduce dezincification, a corrosion process where zinc is selectively leached out of the brass.

The most common naval brass grade is C46400, often called naval brass 464. A typical composition is roughly 60% copper, 39% zinc, and 1% tin, though exact chemistry depends on the applicable specification. The copper provides corrosion resistance and ductility, the zinc adds strength and hardness, and the tin improves performance in wet, chloride-containing, or mildly aggressive environments.

Naval brass is commonly used for marine hardware, propeller shafts, valve stems, pump components, fittings, fasteners, nuts, bolts, washers, rivets, turnbuckles, and structural marine parts. It is especially useful where a part needs better corrosion resistance than ordinary brass but does not necessarily require stainless steel or bronze.

In fastener applications, naval brass is valued because it is corrosion resistant, machinable, non-sparking, and more galvanically compatible with other copper alloys than stainless steel may be in some marine assemblies. However, it is not as strong as alloy steel and is not usually selected for high-strength structural bolting. Its strength is moderate, and its main value is the combination of corrosion resistance, workability, and durability in marine-style service.

Naval brass should not be confused with silicon bronze. Both are copper-based alloys used in marine hardware, but silicon bronze is a copper-silicon alloy with excellent seawater corrosion resistance and is often preferred for premium marine fasteners. Naval brass is generally stronger than some standard brasses and more seawater-resistant because of its tin content, but silicon bronze is often considered superior for long-term saltwater exposure