Copper C120 (Electrolytic Tough Pitch Copper)

Copper C120 (Electrolytic Tough Pitch Copper) is a high-conductivity copper alloy ideal for precision CNC machining applications requiring high conductivity and mechanical strength.

Introduction to Copper C120 (Electrolytic Tough Pitch Copper)

Copper C120, also known as Electrolytic Tough Pitch Copper (ETP Copper), is one of the most commonly used copper alloys in industrial applications. It is known for its excellent electrical conductivity and 100% IACS, making it ideal for electrical and electronic components. The copper is produced through an electrolytic process that enhances its purity, resulting in superior conductivity and relatively high mechanical strength. Copper C120 is often used in CNC machining services to create high-performance components for electrical, telecommunications, and power distribution industries.

Copper C120's superior conductivity and ease of fabrication make it perfect for applications requiring precision and reliability. CNC machined Copper C120 parts are used in cables, busbars, connectors, and other components where electrical efficiency and durability are critical.

Chemical, Physical, and Mechanical Properties of Copper C120 (Electrolytic Tough Pitch Copper)

Chemical Composition (Typical)

Element	Composition Range (wt.%)	Key Role
Copper (Cu)	≥99.90%	Provides high electrical conductivity
Oxygen (O)	≤0.02%	Trace element, enhances conductivity
Other Elements	≤0.10%	Residual elements with minimal impact on properties

Physical Properties

Property	Value (Typical)	Test Standard/Condition
Density	8.92 g/cm³	ASTM B311
Melting Point	1,083°C	ASTM E29
Thermal Conductivity	398 W/m·K at 20°C	ASTM E1952
Electrical Conductivity	100% IACS at 20°C	ASTM B193
Coefficient of Expansion	16.8 µm/m·°C	ASTM E228
Specific Heat Capacity	380 J/kg·K	ASTM E1269
Elastic Modulus	120 GPa	ASTM E111

Mechanical Properties (Annealed Temper)

Property	Value (Typical)	Test Standard
Tensile Strength	210–290 MPa	ASTM E8/E8M
Yield Strength (0.2%)	150–250 MPa	ASTM E8/E8M
Elongation	25–40%	ASTM E8/E8M
Hardness	40–60 HB	ASTM E10
Fatigue Strength	~150 MPa	ASTM E466
Impact Resistance	Good	ASTM E23

Note: These values are typical for annealed Copper C120 and can vary based on specific processing conditions.

Key Characteristics of Copper C120 (Electrolytic Tough Pitch Copper)

Excellent Electrical Conductivity

Copper C120 provides 100% IACS electrical conductivity, superior to other copper alloys like C101, making it ideal for electrical components.

High Ductility and Formability

Compared to alloys like C110, Copper C120 offers superior ductility and can be easily formed into complex shapes without compromising strength.

High Purity for Reliable Performance

The electrolytic process ensures extremely high purity, enhancing performance over materials with lower purity, such as C102.

Moderate Strength with High Toughness

Copper C120 offers moderate tensile strength, making it more suitable for applications requiring flexibility and toughness than harder, less ductile alloys.

Cost-Effective for Electrical Applications

Copper C120 is more cost-effective than higher-strength copper alloys, making it a preferred choice for mass production of electrical parts.

CNC Machining Challenges and Solutions for Copper C120 (Electrolytic Tough Pitch Copper)

Machining Challenges

Soft Material

Copper C120’s softness can lead to material deformation, especially when subjected to high-speed machining processes.

Solution: Use sharp tools and moderate cutting speeds to reduce deformation and ensure consistent machining quality.

Work Hardening

Copper C120 may work harden when subjected to prolonged cutting, making further machining difficult.

Solution: Use moderate cutting speeds, apply sufficient coolant, and maintain sharp cutting edges to prevent work hardening.

Tool Wear

Although soft, Copper C120’s high thermal conductivity can cause significant tool wear during high-speed cutting operations.

Solution: Use carbide tools and apply a sufficient coolant flow to prevent heat buildup and extend tool life.

Chip Formation

Long, stringy chips can form during machining, interfering with the process and causing material buildup.

Solution: Employ chip breakers and optimize coolant flow to facilitate smooth chip removal.

Optimized Machining Strategies

Tool Selection

Parameter	Recommendation	Rationale
Tool Material	Carbide tools	Carbide tools resist wear and extend tool life
Geometry	Positive rake, sharp edges	Improves chip flow and reduces material buildup
Cutting Speed	150–250 m/min	Prevents excessive heating and extends tool life
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 C120 Cutting Parameters (ISO 513 Compliance)

Operation	Speed (m/min)	Feed (mm/rev)	Depth of Cut (mm)	Coolant Pressure (bar)
Roughing	150–200	0.15–0.20	2.0–3.5	30–40
Finishing	200–250	0.05–0.10	0.5–1.0	35–50

Typical Machining Methods for Copper C120 (Electrolytic Tough Pitch Copper)

Machining Process	Function and Benefit for Copper C120 (Electrolytic Tough Pitch Copper)
CNC Machining	Achieves tight tolerances for electrical connectors and parts requiring high conductivity.
CNC Milling	Ideal for producing slots and grooves for electrical components and busbars.
CNC Turning	Suitable for turning cylindrical parts, such as connectors and terminals.
CNC Drilling	Processes holes with high precision for electrical parts and high-current connectors.
CNC Boring	Ideal for internal bore machining with tight tolerances and smooth finishes.
CNC Grinding	Provides fine surface finishes for mechanical and electrical components.
Multi-Axis Machining	Ideal for producing complex electrical components with multiple features and tight tolerances.
Precision Machining	Delivers ultra-tight tolerances for demanding applications in electrical components.
EDM Machining	Used for creating intricate features in small-scale electrical components.

Surface Treatment for Copper C120 CNC Parts

Electroplating: Adds a nickel or gold coating for enhanced corrosion resistance and durability in electrical components.
Polishing: Achieves smooth, glossy finishes with Ra 0.2–0.4 µm for improved electrical conductivity and aesthetic appeal.
Brushing: Provides a uniform satin finish for decorative and functional electrical parts.
PVD Coating: Adds a 2–5 µm durable coating to improve wear resistance and protect the parts in harsh environments.
Passivation: Enhances corrosion resistance, making Copper C120 suitable for outdoor and marine applications.
Powder Coating: Provides a protective 50–100 µm coating for durability and enhanced UV resistance.
Teflon Coating: Adds a low friction, chemical-resistant layer for parts exposed to moving or sliding conditions.
Chrome Plating: Adds a shiny, durable finish (10–20 µm thickness) for high-load applications requiring corrosion protection.

Industry Applications of Copper C120 (Electrolytic Tough Pitch Copper)

Aerospace Industry: Used in high-performance connectors and components for avionics and aerospace systems that require excellent electrical conductivity.
Electrical & Power: Ideal for power generation and distribution systems, including busbars, electrical cables, and connectors.
Telecommunications Industry: Suitable for producing electrical connectors and switchgear used in telecommunications equipment.