Naval Brass Plaques
Where the ocean meets permanence. Naval brass brings a warm, brilliant gold tone and unmatched resistance to salt-air corrosion — the premier choice for marine, waterfront, and coastal installations worldwide.
Naval Brass
· C46400 · ASTM B171
Brass Plaques
WHAT IS C46400 NAVAL BRASS?
Our naval brass plaques use C46400 naval brass — a time-honored copper-zinc-tin alloy also known as “Tobin Bronze” in the foundry trade. This specific alloy has been the gold standard for marine hardware and coastal architectural work since the 19th century, chosen for its remarkable resistance to dezincification and salt-water corrosion.
The 60% copper base gives naval brass its characteristic warm, deep gold appearance — richer and more complex than yellow brass. The critical addition of tin (0.75%) provides the “naval” designation, forming a protective barrier that defeats the chloride corrosion mechanisms that destroy lesser alloys in salt-air environments.
Indus Metal Plaques manufactures naval brass plaques for port authorities, naval installations, yacht clubs, waterfront developments, and any application where proximity to salt water demands an alloy that performs as well as it looks.
Alloy Composition by Weight
Why these ratios? The 60/39.25/0.75 formula is the classic naval brass balance — proven in naval shipbuilding since the 1800s. Copper provides the corrosion resistance; zinc brightens and strengthens the alloy; tin specifically inhibits dezincification in marine chloride environments, which is the failure mode of ordinary brass near salt water.
The Aging Process
How NAVAL BRASS Ages Beautifully
Naval brass develops a richer, warmer patina than standard bronze — a visible record of time, service, and sea air that grows more distinguished with every passing year.
Fresh Cast
Freshly cast naval brass gleams with a rich, warm yellow-gold — brighter than bronze, deeper than regular brass.
1–3 Years
Oxidation deepens the surface to rich amber-gold. The metal begins developing its protective oxide layer
5–15 Years
The patina deepens to rich dark umber and chocolate tones. The oxide layer is now substantial and actively protecting the metal.
20–50 Years
In humid environments, green verdigris begins to appear — particularly in recesses and corners. Widely considered the mark of true age and prestige.
50–100+ Years
The full green-grey patina of historic bronze — the Statue of Liberty is an example. The plaque is now fully self- sealed and effectively immortal.
Full Specifications
Technical Data
Property
Value
Alloy Designation
C46400 (ASTM B171)
Composition
60% CU · 39.25% ZN · 0.75% SN
Casting Method
| Sand Casting, Chemically-Bonded Mold |
Pour Temperature
1,650°F (899°C)
Tensile Strength
55,000 PSI
Density
0.304 LB/IN³ (~8.41 G/CM³)
Standard Thickness
| 3/8 inch Base Field |
Relief Height
Up to 3/4 inch (Title Letters)
Background Color
Hunter Green (RAL 6009), baked enamel
Clearcoat System
Marine-grade polyurethane, 25-yr rating
Mounting
Stainless 3/8″ anchor bolts (template incl.)
Outdoor Lifespan
100+ years documented
Warranty
Lifetime — full replacement
Note: The material specifications, alloy composition, and performance characteristics provided are for general reference only. Actual composition, mechanical properties, finishes, and aging behavior may vary based on manufacturing processes, environmental conditions, and application. Natural patina development and color changes in bronze will differ over time.
Why Choose Bronze
Seven Reasons Bronze Wins
True Marine-Grade Alloy
C46400 was engineered specifically for salt-water service. Its tin content blocks the dezincification that destroys ordinary brass in marine environments
Richest Gold Appearance
Superior Tensile Strength
At 55,000 PSI, naval brass outperforms both bronze and aluminum in tensile strength — exceptional for high-detail bas-relief and portrait work.
Coastal Corrosion Immunity
The tin in C46400 forms a protective layer that specifically resists chloride ion attack — the primary corrosion mechanism in coastal and marine environments.
Coastal Durability
Outperforms aluminum in salt-air environments. The copper alloy resists chloride corrosion that can pit and degrade aluminum alloys over time.
Historic Naval Pedigree
Used in U.S. Navy ships, port facilities, and waterfront monuments since the 1800s. This material carries authentic maritime heritage and institutional authority
Distinctive Patina Character
Naval brass develops a warmer, more complex patina than standard bronze — the green verdigris against deep amber creates a striking two-tone aged effect.