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China Brass CNC Machining Service - Reliable Factory Suppliers for High-Precision Bronze Components
Common Bronze Alloy Grades and Characteristics
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 (FAQ)
Q
What is the difference between bronze and brass, and how do I choose the right one?
Bronze is primarily a copper-tin (or copper-aluminum/silicon) alloy, while brass is a copper-zinc alloy. Bronze generally offers higher strength, a lower friction coefficient, and better corrosion resistance—especially in seawater. Brass tends to be easier to machine and more cost-effective for decorative or low-load parts. Choose bronze for heavy-duty, wear-critical, or corrosive environments, and brass for moderate-duty or aesthetic applications.
Q
Which bronze grade is best suited for bearing and bushing applications?
C93200 / SAE 660 (High-Leaded Tin Bronze) is the most widely used grade for bearings and bushings. Its high lead content creates soft particles within the alloy matrix, providing outstanding self-lubrication and anti-galling performance—ideal for high-load, low-speed, or poorly lubricated conditions.
Q
Can aluminum bronze (C95400) be used in marine environments?
Yes. C95400 Aluminum Bronze is one of the best choices for marine applications. It offers excellent resistance to seawater corrosion and cavitation erosion, making it a preferred material for marine propellers, pump housings, valve seats, and other seawater-exposed components. Its strength is also comparable to low-alloy steel, providing added structural reliability.
Q
What makes phosphor bronze (C54400) suitable for electrical and spring components?
Phosphor bronze contains a small but critical addition of phosphorus, which significantly enhances the alloy's elastic limit, fatigue strength, and wear resistance. This results in excellent spring-back characteristics and dimensional stability under cyclic loading—making it ideal for electrical connectors, springs, diaphragms, bellows, and precision gears where consistent performance over millions of cycles is required.
Q
Is high-silicon bronze (C65500) weldable, and what industries commonly use it?
Yes, C65500 High-Silicon Bronze is notably one of the most weldable copper alloys available. It can be welded using MIG, TIG, and other conventional methods with excellent results. It is widely used in the chemical processing industry (especially where sulfuric acid and sulfate resistance is needed), marine hardware, heat exchangers, pump and valve components, and fabricated structural parts requiring both strength and corrosion resistance.
Q
Can you machine custom bronze parts from prototypes to small-batch production?
Absolutely. Our CNC machining centers are fully equipped to process all the bronze alloy grades listed above—including C93200, C95400, C54400, and C65500. We support everything from one-off complex prototypes to small and medium-batch production runs, ensuring tight tolerances, excellent surface finishes, and consistent material quality throughout each order.
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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