Brass and bronze are two of the most widely used copper alloys in precision manufacturing — and while they're often mentioned in the same breath, they perform very differently in the field. Choosing the right alloy for a given application isn't just about cost or availability; it's about matching the material's properties to the demands of the job.
This guide covers the key differences between brass and bronze, highlights the grades we rely on most at Admiral Metals — including C360's industry-leading machinability, C954's outstanding corrosion resistance, and the growing shift from C360 to C2745 for lead-free applications — and gives you a practical framework for making the right call.
The Fundamental Difference
Both are copper alloys, but the alloying elements define everything:
Copper–Zinc Alloy
Brass
Cu + Zn
Bright golden appearance, excellent machinability, and strong corrosion resistance in everyday environments. The go-to choice for high-volume precision machining.
Copper–Tin Alloy
Bronze
Cu + Sn (+ Al, Ni, Si…)
Harder, stronger, and superior in harsh or submerged environments. The specialist alloy for marine, industrial, and heavy-load applications.
Zinc (brass) favors cost, machinability, and electrical conductivity. Tin, aluminum, or silicon (bronze) favors strength, wear resistance, and corrosion performance under demanding conditions.
Key Property Comparison
| Property |
Brass |
Bronze |
| Machinability |
|
|
| Corrosion Resistance |
|
Excellent (marine, acids)
|
| Hardness / Wear |
|
|
| Material Cost |
|
|
| RoHS / Lead-Free |
C360: contains lead · C2745: fully compliant |
C954: compliant |
Brass Grades: What You Need to Know
C360 — Free-Cutting Brass: The Machinability Benchmark
Free-Machining Brass
C360 — Alloy 360 / Free-Cutting Brass
The industry-standard for high-speed, high-volume machining
- Machinability rated at ~100% — the universal benchmark against which all other copper alloys are measured
- Contains ~3% lead, which acts as a built-in chip-breaker and internal lubricant during cutting operations
- Produces short, manageable chips — critical for screw machines and high-speed CNC turning centers
- Dramatically extends tool life and enables faster cycle times versus other copper alloys
- Delivers excellent surface finish with minimal secondary operations required
- Ideal for fittings, valves, fasteners, gears, and general-purpose machined components
- Limitation: Not RoHS compliant — restricted in potable water plumbing, EU-exported products, and medical applications
Why C360 Machines So Well
The lead particles in C360 don't dissolve into the copper matrix — they remain as tiny dispersed inclusions that act as a chip-breaker and internal lubricant at the cutting edge. The result: short, manageable chips instead of the long stringy swarf that plagues other alloys, dramatically reduced tool wear, faster cycle times, and a superior surface finish right off the machine. For high-volume screw machine work or CNC turning, no other copper alloy delivers this combination of speed, finish quality, and cost efficiency.
C2745 — Lead-Free Eco Brass: The Modern Alternative
C360 — Free-Cutting Brass
The traditional choice
~3% lead content · Machinability ~100% · Not RoHS or NSF 61 compliant · Restricted in potable water and EU applications
→
Recommended Upgrade
C2745 — Eco Brass
The lead-free standard
<0.09% lead · Machinability ~70–80% of C360 · Fully RoHS, NSF 61 & California AB 1953 compliant · Drop-in replacement for most machined parts
Compliance Note
As regulations around lead in plumbing and potable water systems have tightened — particularly under NSF/ANSI 61, the EU's RoHS directive, and California's AB 1953 (Prop 65 "Lead-Free" standard) — the industry has been steadily migrating away from C360 for these applications. C2745 is the primary engineered replacement: it retains excellent machinability (~70–80% of C360), fits the same stock forms and tolerances, and requires no significant design changes in most cases.
Other Key Brass Grades
Naval Brass
C464
Naval Brass
- Tin addition significantly improves seawater corrosion resistance over standard brass
- Common in marine hardware, propeller shafts, and condenser tubes
- Good combination of strength and formability
Cartridge Brass
C260
70/30 Cartridge Brass
- Exceptional cold-working and deep-draw capability
- Used for ammunition casings, radiator cores, springs, and stampings
- Good corrosion resistance; moderate machinability
Bronze Grades: Strength Where It Counts
C954 — Aluminum Bronze: The Corrosion Resistance Leader
Aluminum Bronze
C954 — Alloy 954 / Aluminum Bronze
The premium choice for marine, chemical, and high-stress environments
- Outstanding corrosion resistance — resists seawater, mild acids, and high-temperature oxidation
- Aluminum content (~9–11%) forms a tenacious, self-healing oxide layer similar in principle to stainless steel
- High tensile strength (~85 ksi) combined with excellent wear and erosion resistance
- Preferred for pump impellers, propellers, marine shafting, valves, and chemical plant components
- Inherently corrosion-resistant throughout its cross-section — not dependent on coatings or plating
- Lead-free and fully compliant with environmental regulations
- Well-suited for heavy structural and flow-exposed parts where coating integrity cannot be guaranteed
Why C954 Outperforms in Corrosive Environments
The aluminum content in C954 creates a dense, tightly adhering aluminum oxide surface layer that reforms instantly if the surface is scratched or abraded — providing robust, self-repairing protection in saltwater, mild acids, and oxidizing atmospheres. Unlike many alloys that rely on surface coatings for corrosion protection, C954 is corrosion-resistant throughout its entire cross-section. This makes it the material of choice for pump components, propeller hubs, marine shafting, and any application where coating integrity cannot be reliably maintained.
Other Key Bronze Grades
Tin Bronze
C932
SAE 660 · High-Leaded Tin Bronze
- The workhorse bearing bronze — conformable, low friction, embeds contaminants
- Excellent for bushings, washers, and thrust bearings under moderate loads
- Available in oil-impregnated form for self-lubricating applications
Phosphor Bronze
C510 / C544
Phosphor Bronze
- Phosphorus addition increases hardness and significantly improves fatigue resistance
- Excellent for springs, electrical contacts, and fine wire mesh
- Good corrosion resistance in both fresh and salt water
Silicon Bronze
C651 / C655
Silicon Bronze
- Outstanding weldability — preferred for architectural and artistic fabrication
- Good strength and corrosion resistance
- Used in marine fasteners, bolts, and sculpture
Bearing Bronze
C863
Manganese Bronze
- Very high strength — among the strongest of all copper alloys
- Used for heavy-duty gears, wear plates, and structural hardware
- Good resistance to dezincification in seawater
When to Use Each: A Practical Guide
Choose Brass When…
- High-volume precision machining is the priority (C360 or C2745)
- Electrical or thermal conductivity matters for the design
- Aesthetic / decorative finish is important (warm golden color)
- Cost is a primary constraint on the project
- Mild corrosion environments — air, fresh water, indoor service
- Lead-free compliance is required → specify C2745 or C464
- Plumbing fittings, HVAC components, instrumentation
- Locks, gears, ammunition casings, musical instruments
Choose Bronze When…
- Marine or submerged saltwater exposure is a factor (C954, C464)
- High wear, bearing, or bushing performance is required (C932, C954)
- Elevated temperature or chemical plant service conditions apply
- Heavy structural parts require high tensile strength
- Pump impellers, propellers, shafts, valves in aggressive media
- Springs and electrical contacts needing fatigue resistance (C510)
- Welded assemblies and architectural or artistic work (C655)
- Inherent corrosion resistance is needed throughout the cross-section
Quick Grade Reference
Best Machinability
C360
Free-cutting brass
Lead-Free Machining
C2745
Eco brass / RoHS
Best Corrosion Resistance
C954
Aluminum bronze
Best Bearing Performance
C932
SAE 660 tin bronze
The Bottom Line
Brass and bronze aren't interchangeable — they're complementary. Brass wins on machinability, cost, and everyday corrosion resistance, making it the default choice for precision machined parts in benign environments. Bronze wins in demanding conditions: marine exposure, heavy loads, bearing surfaces, and anywhere a coating simply can't be relied upon.
Within each family, grade selection matters just as much as alloy family. C360 remains the machining benchmark, but C2745 is becoming the responsible default for any application touching potable water or destined for regulated markets. And when corrosion or wear is the design driver, C954 aluminum bronze is in a class of its own among copper alloys.
Not sure which grade is right for your next job? Our team has been matching customers to the right material since 1950 — give us a call or request a quote online.
Ready to Order or Need a Recommendation?
Admiral Metals stocks a full range of brass and bronze alloys in rod, bar, tube, and plate — cut to your exact requirements.
Admiral Metals has a unique customer-focused operating philosophy that has been at the foundation of its warehouse practices for many years. The Company’s production is based on the customer need for delivery the next day, unlike most companies that are focused solely on driving yield. “A fast turnaround means our production is streamlined with minimal overstock,” says Don Bishop, Operations Manager.