Copper C260 (Brass)
Introduction to Copper C260 (Brass)
Copper C260, commonly known as cartridge brass, is a highly versatile brass alloy primarily composed of 70% copper and 30% zinc. This alloy is known for its excellent machinability, good corrosion resistance, and superior strength. Copper C260 is widely used in applications where moderate strength and good electrical conductivity are essential, such as in electrical connectors, plumbing, and automotive parts. Its balance of properties makes it suitable for both decorative and functional applications.
Copper C260 (Brass) is often selected for use in CNC machining due to its ease of machining, ability to be formed into complex shapes, and excellent surface finish. This makes it ideal for applications in industries such as manufacturing, automotive, aerospace, and electronics, where high-performance parts are required. The alloy’s excellent workability also makes it a top choice for producing CNC-machined brass components in various applications.
Chemical, Physical, and Mechanical Properties of Copper C260 (Brass)
Chemical Composition (Typical)
Element | Composition Range (wt.%) | Key Role |
|---|---|---|
Copper (Cu) | 70% | Provides excellent electrical and thermal conductivity |
Zinc (Zn) | 30% | Enhances strength, hardness, and corrosion resistance |
Other Elements | ≤0.5 | Residual elements with minimal impact on properties |
Physical Properties
Property | Value (Typical) | Test Standard/Condition |
|---|---|---|
Density | 8.5 g/cm³ | ASTM B311 |
Melting Point | 900°C | ASTM E29 |
Thermal Conductivity | 120 W/m·K at 20°C | ASTM E1952 |
Electrical Conductivity | 28% IACS at 20°C | ASTM B193 |
Coefficient of Expansion | 19.0 µm/m·°C | ASTM E228 |
Specific Heat Capacity | 380 J/kg·K | ASTM E1269 |
Elastic Modulus | 110 GPa | ASTM E111 |
Mechanical Properties (Annealed Temper)
Property | Value (Typical) | Test Standard |
|---|---|---|
Tensile Strength | 380–550 MPa | ASTM E8/E8M – full-section test specimens |
Yield Strength (0.2%) | 275–380 MPa | ASTM E8/E8M – offset method |
Elongation | 35–50% | ASTM E8/E8M – gauge length = 50 mm |
Hardness | 70–85 HB | ASTM E10 – Brinell hardness, 10 mm ball/500 kg load |
Fatigue Strength | ~240 MPa | ASTM E466 – rotating bending fatigue at 10⁷ cycles |
Impact Resistance | Good | ASTM E23 – Notched, room temperature |
Note: These values are typical for annealed Copper C260 (Brass) and can vary based on specific processing conditions.
Key Characteristics of Copper C260 (Brass)
High Strength and Durability
Copper C260 offers a higher tensile strength compared to pure copper, making it a suitable material for applications that require enhanced mechanical properties. The alloy’s strength, ranging from 380–550 MPa, makes it durable enough for demanding applications like automotive components, electrical terminals, and fasteners.
Excellent Workability and Machinability
Copper C260 (Brass) has excellent machinability, making it ideal for CNC machining. It is easily formed into complex geometries and holds tight tolerances, which is crucial for precision components used in industries like electronics, plumbing, and hardware manufacturing. This alloy is especially easy to machine and shape into parts like connectors, valve stems, and screws.
Corrosion Resistance
Copper C260 offers good corrosion resistance in various environments, including fresh and saltwater environments. This makes it suitable for components used in plumbing, marine, and electrical applications, where corrosion resistance is a critical factor for long-term reliability.
Moderate Electrical and Thermal Conductivity
Although Copper C260 is not as conductive as pure copper, it still offers moderate electrical and thermal conductivity, which makes it suitable for electrical connectors and components that require efficient heat dissipation. With 28% IACS electrical conductivity, it performs well in applications where conductivity and strength are both important.
Attractive Appearance and Finishing
Copper C260 has an attractive golden-yellow appearance, making it an excellent choice for decorative applications like jewelry, hardware, and ornaments. Its ease of polishing and surface finishing also makes it ideal for parts that require a shiny, aesthetically pleasing surface.
CNC Machining Challenges and Solutions for Copper C260 (Brass)
Machining Challenges
Work Hardening
Copper C260 (Brass) can work-harden during machining, which can make further processing more difficult, increase tool wear, and affect surface quality.
Solution: Use sharp tools and avoid excessive deformation. Lower cutting speeds and apply adequate coolant to reduce heat buildup and prevent work hardening.
Chip Formation
Copper C260 tends to produce long chips that can interfere with the machining process and require constant management.
Solution: Use chip breakers and maintain a steady coolant flow to enhance chip removal. This will prevent chips from wrapping around the tool and interfering with the operation.
Tool Wear
Despite its machinability, Copper C260 can cause tool wear, especially when machining at high speeds.
Solution: Use carbide tools with appropriate coatings, such as TiAlN, to reduce wear and extend tool life. Additionally, controlling cutting speeds and feed rates will help manage tool wear.
Optimized Machining Strategies
Tool Selection
Parameter | Recommendation | Rationale |
|---|---|---|
Tool Material | Carbide tools with TiAlN coating | Increases tool lifespan and reduces wear in tough materials |
Geometry | Positive rake, sharp edges | Improves chip flow and reduces material buildup |
Cutting Speed | 200–300 m/min | Prevents excessive heating and enhances tool longevity |
Feed Rate | 0.15–0.25 mm/rev | Ensures smooth cutting and prevents material deformation |
Coolant | Flood coolant or air blast | Reduces heat buildup and aids in chip removal |
Copper C260 Cutting Parameters (ISO 513 Compliance)
Operation | Speed (m/min) | Feed (mm/rev) | Depth of Cut (mm) | Coolant Pressure (bar) |
|---|---|---|---|---|
Roughing | 180–220 | 0.10–0.20 | 2.0–3.5 | 25–40 (Flood coolant) |
Finishing | 250–300 | 0.05–0.10 | 0.5–1.0 | 30–50 (Flood coolant) |
Typical Machining Services for Copper C260 (Brass)
Copper C260 (Brass) is ideal for various CNC machining services that require high precision and mechanical strength. Below are the typical machining services:
Machining Process | Suitability for Copper C260 (Brass) |
|---|---|
Ideal for producing electrical connectors, fasteners, and intricate parts with good conductivity and strength | |
Suitable for machining flat surfaces, pockets, and complex shapes with excellent precision | |
Excellent for producing cylindrical parts such as rods, tubes, and threaded components | |
Perfect for drilling precise holes with minimal burr formation in brass components | |
Ideal for enlarging holes with tight tolerances and a smooth surface finish | |
Achieves superior surface finishes and tight tolerances on brass parts | |
Enables the production of complex parts in a single setup, ensuring precision and efficiency | |
Provides the tightest tolerances for critical components used in various industries | |
Ideal for intricate parts that require fine details and precision, especially when traditional machining is difficult |
Surface Treatment for Copper C260 CNC Parts
Electroplating: Enhances wear resistance and corrosion protection by applying a thin coating of metals such as nickel, silver, or gold.
Polishing: Achieves a smooth, reflective finish that enhances the appearance and functionality of brass components.
Brushing: Provides a satin or matte finish that reduces surface glare and enhances the appearance of decorative components.
PVD Coating: Adds superior durability, wear resistance, and an aesthetically pleasing finish for visible parts.
Passivation: Improves the corrosion resistance of brass parts by removing contaminants from the surface.
Powder Coating: Provides durable protection from wear and environmental factors for components exposed to harsh conditions.
Teflon Coating: Ideal for parts that require chemical resistance and non-stick properties.
Chrome Plating: Adds strength and durability while providing a shiny, corrosion-resistant surface.
Industry Applications of Copper C260 (Brass)
Automotive Industry: Copper C260 (Brass) is widely used in automotive applications, including engine components, electrical terminals, connectors, and other high-performance parts requiring strength, corrosion resistance, and good electrical conductivity.
Electrical & Power Distribution: Used for electrical connectors, busbars, and terminals, where both strength and conductivity are essential for reliable electrical power distribution.
Plumbing & Hardware: Ideal for producing plumbing components like faucets, valves, and fittings, as well as ornamental hardware where aesthetics and durability are essential.
FAQs
How does Copper C260 (Brass) compare to other copper alloys in terms of strength?
What are the key benefits of using Copper C260 in electrical applications?
Can Copper C260 be used for high-temperature applications?
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What are the best surface treatments for Copper C260 to enhance its durability?
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