+86-13928348837
China Bronze CNC Machining Services | Reliable Suppliers & Factory for High-Quality Industrial Parts
Bronze typically refers to a family of alloys with copper as the base, primarily alloyed with elements such as tin, aluminum, silicon, and manganese. Compared to brass (copper-zinc alloys), bronze generally offers higher strength, a lower coefficient of friction, and better chemical corrosion resistance (especially against seawater). Its outstanding wear resistance and self-lubricating properties make it irreplaceable in bearing and bushing applications.
1. C93200 / SAE 660 (High-Leaded Tin Bronze - Bearing Bronze)
●Characteristics: This is the most widely used bearing bronze. The added lead forms soft particles within the alloy, providing excellent self-lubricating and anti-galling properties, making it ideal for operation under insufficient lubrication or high-load, low-speed conditions. It is easy to machine and offers good wear resistance.
●Typical Applications: General-purpose bearings, bushings, thrust washers, pump components, low-load gears.
C93200 Typical Properties (As Sand-Cast)
| Property | Value | Notes |
|---|---|---|
| Tensile Strength (MPa) | 240 – 330 | Good overall strength |
| Yield Strength (0.5% Extension, MPa) | 124 | |
| Elongation at Break (%) | 18 | Good ductility |
| Hardness (Brinell) | 65 | |
| Density (g/cm³) | 8.93 | |
| Key Composition | Cu-83%, Sn-7%, Pb-7%, Zn-3% | High lead content provides self-lubrication |
| Note: Values are typical ranges, specific to casting and processing conditions. | ||
2. C95400 (Aluminum Bronze)
●Characteristics: A high-strength, high-hardness aluminum bronze. Its corrosion resistance, wear resistance, and fatigue strength are among the best of all bronzes, with performance comparable to many steels. It retains strength at elevated temperatures and offers excellent impact and cavitation resistance.
●Typical Applications: Heavy-duty bearings, gears, valve seats, pump housings, propellers and components for seawater use, chemical processing equipment.
C95400 Typical Properties (Heat-Treated Condition)
| Property | Value | Notes |
|---|---|---|
| Tensile Strength (MPa) | 620 – 760 | Very high strength, comparable to low-alloy steels |
| Yield Strength (0.2% Offset, MPa) | 275 | |
| Elongation at Break (%) | 12–18 | |
| Hardness (Brinell) | 170 – 210 | High hardness, very wear-resistant |
| Density (g/cm³) | 7.45 | Lighter than tin bronze |
| Key Composition | Cu-85%, Al-11%, Fe-4% | Tin-free, uses aluminum and iron as main alloying elements |
| Note: Values are typical ranges, specific to heat treatment condition. | ||
3. C54400 (Phosphor Bronze)
●Characteristics: A tin bronze containing a small amount of phosphorus. Phosphorus increases the alloy's elastic limit, fatigue strength, and wear resistance. This material offers excellent spring properties, good wear and corrosion resistance, and is easily machined into precision parts.
●Typical Applications: Electrical connectors, springs, diaphragms, bellows, wear plates, precision gears.
C54400 Typical Properties (Cold Worked Condition)
| Property | Value | Notes |
|---|---|---|
| Tensile Strength (MPa) | 520 – 690 | High strength, especially suitable for elastic elements |
| Yield Strength (0.2% Offset, MPa) | 380 – 550 | High yield strength |
| Elongation at Break (%) | 10–15 | |
| Hardness (Rockwell B) | 78 – 90 | |
| Density (g/cm³) | 8.8 | |
| Key Composition | Cu-88%, Sn-4%, Zn-4%, P-0.2–0.5% | Phosphorus acts as a deoxidizer and enhances properties |
| Note: Values are typical ranges, specific to the degree of cold work. | ||
4. C65500 (High-Silicon Bronze)
●Characteristics: A bronze with excellent corrosion resistance, particularly outstanding in sulfuric acid and sulfate environments. It combines high strength, high corrosion resistance, and good formability and weldability, making it widely used in chemical and marine industries.
●Typical Applications: Chemical processing equipment components, heat exchanger tube sheets, marine fittings, pump valves, fasteners, welded structures.
❓ Frequently Asked Questions
Q1 What is the difference between bronze and brass?
Bronze is primarily a copper-based alloy alloyed with tin, aluminum, silicon, or manganese, while brass is a copper-zinc alloy. Bronze generally offers higher strength, a lower coefficient of friction, and better corrosion resistance — especially in seawater environments — making it more suitable for heavy-duty mechanical and marine applications.
Q2 Which bronze alloy is best for bearing and bushing applications?
C93200 (SAE 660 High-Leaded Tin Bronze) is the most widely used alloy for bearings and bushings. Its high lead content creates soft particles within the matrix that provide excellent self-lubricating and anti-galling properties, making it ideal for high-load, low-speed, or poorly lubricated operating conditions.
Q3 When should I choose C95400 Aluminum Bronze over other bronze grades?
C95400 Aluminum Bronze should be chosen when high strength, high hardness, and superior corrosion resistance are simultaneously required — particularly for seawater exposure, elevated-temperature service, or heavy-duty mechanical components such as gears, valve seats, pump housings, and propellers. Its tensile strength (620–760 MPa) is comparable to many low-alloy steels.
Q4 What role does phosphorus play in C54400 Phosphor Bronze?
In C54400, phosphorus serves two key functions: it acts as a deoxidizer during casting to improve alloy purity, and it significantly enhances the elastic limit, fatigue strength, and wear resistance of the alloy. This makes Phosphor Bronze especially well-suited for precision springs, electrical connectors, diaphragms, and other components requiring reliable elastic performance.
Q5 Is C65500 High-Silicon Bronze suitable for welded structures?
Yes. C65500 High-Silicon Bronze is one of the most weldable copper alloys available. It combines excellent corrosion resistance (particularly in sulfuric acid and sulfate environments), good formability, and strong weldability, making it a popular choice for fabricated chemical processing equipment, heat exchanger tube sheets, marine fittings, and other welded assemblies.
Q6 How do I select the right bronze alloy grade for my application?
Selecting the right bronze grade depends on your specific requirements: choose C93200 for general bearing/bushing use with self-lubrication needs; C95400 for maximum strength and seawater or high-temperature resistance; C54400 for precision elastic components and electrical connectors; and C65500 for chemical or marine environments requiring excellent corrosion resistance and weldability. Always consult material datasheets and consider the operating load, speed, environment, and fabrication method.
Finishes and Post-Processing Options
The zinc alloy substrate is highly suitable for various surface treatments to enhance decoration, protection, or functionality:
Electroplating: Such as chrome, nickel, gold, or silver plating, providing a highly decorative appearance, excellent wear and corrosion resistance. This is the most common choice.
-
Passivation or Chromate Conversion Coating:
-
Powder Coating:
-
Painting:
-
Physical Vapor Deposition (PVD):
Design and Machining Considerations
-
Process Selection:
-
Design Considerations:
-
Material Selection:
Zamak 3 and 5 are suitable for the vast majority of general-purpose parts requiring good appearance and strength; ZA-8 is better for wear and bearing applications; for making rapid tooling, choose specialized alloys like Kirksite.
Ready to Start Your CNC Project?
Send us your drawings to receive professional manufacturing solutions.