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China Brass CNC Machining Service - Reliable Supplier & Factory for Bronze Components
Bronze generally refers to a group of copper‑based alloys, mainly alloyed with tin, aluminum, silicon, manganese, and other elements. Compared with brass (copper‑zinc alloys), bronze typically features higher strength, a lower friction coefficient, and better chemical corrosion resistance—especially in seawater environments. Thanks to its excellent wear resistance and self‑lubricating properties, it plays an irreplaceable role in bearings and bushings. Our machining centers are well‑equipped to process various bronze materials, supporting high‑quality production from complex prototypes to small‑batch manufacturing.
1. C93200 / SAE 660 — High-Leaded Tin Bronze (Bearing Bronze)
⚙️ Characteristics: This is the most commonly used bearing bronze grade. Lead is added to form soft particles in the alloy structure, delivering exceptional self-lubrication and anti-galling performance. This makes it particularly suitable for applications with insufficient lubrication, or under high-load and low-speed operating conditions. It features good machinability and reliable wear resistance.
🔩 Typical Applications: Suitable for general‑purpose bearings, bushings, thrust washers, pump components, and low‑load gears across various industrial applications.
| 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 |
Values are typical ranges, specific to casting and processing conditions.
2. C95400 — Aluminum Bronze
⚙️ Characteristics: This is a high‑strength, high‑hardness aluminum bronze. It boasts some of the best corrosion resistance, wear resistance, and fatigue strength among all bronze alloys, with performance comparable to many steel materials. It maintains its strength at elevated temperatures and delivers excellent resistance to impact and cavitation.
🔩 Typical Applications: Ideal for heavy-duty bearings, gears, valve seats, pump housings, marine propellers and seawater-resistant components, as well as various parts used in chemical processing equipment.
| 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 |
Values are typical ranges, specific to heat treatment condition.
3. C54400 — Phosphor Bronze
⚙️ Characteristics: This is a tin bronze with a small addition of phosphorus. Phosphorus enhances the alloy's elastic limit, fatigue strength, and wear resistance. The material exhibits excellent spring characteristics, good wear and corrosion resistance, and can be readily machined into precision components.
🔩 Typical Applications: Perfect for electrical connectors, springs, diaphragms, bellows, wear plates, and high-precision gears across multiple industrial applications.
| 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 |
Values are typical ranges, specific to the degree of cold work.
4. C65500 — High-Silicon Bronze
⚙️ Characteristics: This bronze features exceptional corrosion resistance, especially in sulfuric acid and sulfate environments. It combines high strength, excellent corrosion resistance, good formability and weldability, making it widely applied in the chemical and marine industries.
🔩 Typical Applications: Ideal for components in chemical processing equipment, heat exchanger tube sheets, marine hardware and fittings, pump and valve parts, fasteners, as well as welded structural parts.
Frequently Asked Questions
Q
What is the main difference between C93200 bearing bronze and other bronze alloys?
C93200 (SAE 660) is specifically formulated with a high lead content (approximately 7%), which creates soft particles within the alloy matrix. This gives the material exceptional self-lubricating and anti-galling properties, making it the preferred choice for bearings and bushings operating under insufficient lubrication, high-load, or low-speed conditions—performance characteristics that most other bronze grades do not offer to the same degree.
Q
Why is C95400 Aluminum Bronze compared to steel in terms of strength?
C95400 achieves a tensile strength of 620–760 MPa, which is comparable to many low-alloy steels. The combination of aluminum (11%) and iron (4%) as primary alloying elements significantly enhances its mechanical properties, including hardness (170–210 HB), fatigue strength, and impact resistance. It also retains these properties at elevated temperatures, making it a viable metal alternative in demanding structural applications.
Q
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 the purity and soundness of the alloy, and it enhances the material's elastic limit, fatigue strength, and wear resistance. These qualities make phosphor bronze particularly well-suited for precision spring components, electrical connectors, and high-cycle mechanical parts where fatigue performance is critical.
Q
Which bronze alloy is best suited for marine or seawater applications?
Both C95400 Aluminum Bronze and C65500 High-Silicon Bronze are excellent choices for marine environments. C95400 offers outstanding resistance to seawater corrosion and cavitation, making it ideal for marine propellers and pump housings. C65500 provides superior resistance in chemically aggressive environments including sulfuric acid and sulfate solutions, and its excellent weldability makes it suitable for marine structural assemblies and fittings.
Q
Can these bronze alloys be used for CNC machining and precision manufacturing?
Yes. All four bronze grades—C93200, C95400, C54400, and C65500—are compatible with CNC machining processes. C93200 and C54400 are particularly noted for their good machinability, while C95400 and C65500 may require more robust tooling due to their higher hardness and strength. Our machining centers are equipped to handle all these materials, supporting everything from complex prototype development to small-batch precision manufacturing.
Q
How do I choose the right bronze alloy grade for my application?
Selecting the right bronze grade depends on your specific operating conditions. For low-speed, high-load bearing applications with limited lubrication, C93200 is the standard choice. For heavy-duty structural or marine components requiring high strength and hardness, C95400 is recommended. If your application demands excellent spring properties or electrical conductivity, C54400 Phosphor Bronze is ideal. For chemical processing or welded assemblies in corrosive environments, C65500 High-Silicon Bronze offers the best performance. Consulting with a materials specialist or machining partner can help ensure the optimal selection.
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.
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Passivation or Chromate Conversion Coating:
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Powder Coating:
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Painting:
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Physical Vapor Deposition (PVD):
Design and Machining Considerations
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Process Selection:
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Design Considerations:
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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.
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