Brass C655

Brass C655 is a high-strength copper-zinc alloy with excellent machinability and corrosion resistance, making it ideal for use in industrial applications such as automotive, plumbing, electrical, and aerospace systems.

Introduction to Brass C655

Brass C655, also known as High-Strength Brass, is a copper-zinc alloy with enhanced strength, making it suitable for applications requiring high mechanical properties. Brass C655 is often alloyed with small amounts of lead, tin, and other elements to improve its machinability, corrosion resistance, and wear resistance. It provides superior strength compared to other brass alloys, making it ideal for critical applications. It is widely used in high-performance industries where parts must endure both mechanical stress and environmental exposure. For precision machining, Brass C655 is an excellent choice due to its high machinability and durability.

Brass C655 is commonly used in CNC machined parts such as industrial fittings, connectors, valves, and bushings. Its excellent strength and machinability make it ideal for automotive, plumbing, and electrical parts, where durability and precision are critical.

Chemical, Physical, and Mechanical Properties of Brass C655

Chemical Composition (Typical)

Element	Composition Range (wt.%)	Key Role
Copper (Cu)	60.0–65.0%	Provides strength, conductivity, and corrosion resistance
Zinc (Zn)	35.0–39.0%	Enhances strength and hardness
Tin (Sn)	0.5–1.5%	Improves corrosion resistance and increases hardness
Lead (Pb)	≤0.2%	Improves machinability and reduces friction during machining
Iron (Fe)	≤0.5%	Minimal impact on properties

Physical Properties

Property	Value (Typical)	Test Standard/Condition
Density	8.5 g/cm³	ASTM B311
Melting Point	900–950°C	ASTM E29
Thermal Conductivity	95 W/m·K at 20°C	ASTM E1952
Electrical Conductivity	10% IACS at 20°C	ASTM B193
Coefficient of Expansion	19 µm/m·°C	ASTM E228
Specific Heat Capacity	380 J/kg·K	ASTM E1269
Elastic Modulus	105 GPa	ASTM E111

Mechanical Properties (Annealed Temper)

Property	Value (Typical)	Test Standard
Tensile Strength	380–480 MPa	ASTM E8/E8M
Yield Strength (0.2%)	250–350 MPa	ASTM E8/E8M
Elongation	20–30%	ASTM E8/E8M
Hardness	70–90 HB	ASTM E10
Fatigue Strength	~220 MPa	ASTM E466
Impact Resistance	Good	ASTM E23

Key Characteristics of Brass C655

Excellent Strength

Brass C655 provides high tensile strength, making it suitable for parts that are subjected to mechanical stress, such as bushings, connectors, and fittings used in the automotive and industrial sectors.

Good Machinability

Brass C655 retains excellent machinability despite its high strength, making it ideal for high-speed CNC machining operations. The material’s low friction properties reduce tool wear and improve productivity.

Corrosion Resistance

Brass C655 exhibits good corrosion resistance, particularly in atmospheric environments. However, its resistance to aggressive chemicals and seawater is lower than alloys like C715, which is more suitable for marine applications.

High Wear Resistance

Brass C655’s durability and resistance to wear make it an ideal choice for applications involving moving parts that undergo frequent contact, such as bushings, bearings, and gears.

Aesthetic Appeal

Brass C655 has a golden-yellow finish, which gives it an attractive appearance. This makes it a popular choice for decorative parts and components that need to perform while maintaining visual appeal.

CNC Machining Challenges and Solutions for Brass C655

Machining Challenges

Chip Formation Brass C655 tends to generate long, stringy chips during machining, which can cause inefficiencies and blockages.
Solution: Use chip breakers and adjust feed rates to reduce chip length. Apply coolant or air to clear chips effectively.
Tool Wear Although Brass C655 is known for its machinability, the hardness of the material can cause tool wear, especially during high-speed cutting operations.
Solution: Use high-performance carbide or ceramic tools to improve tool life and optimize cutting efficiency.
Surface Finish Quality Brass C655 may form rough edges during machining, which can affect the part's surface finish.
Solution: Employ high-speed cutting with sharp, high-quality tools and ensure proper lubrication to achieve smooth finishes.
Work Hardening Brass C655 can experience work hardening if excessive pressure or speed is applied during machining.
Solution: Use moderate cutting speeds, sharp tools, and adequate coolant to minimize work hardening and preserve material integrity.

Optimized Machining Strategies

Parameter	Recommendation	Rationale
Tool Material	Carbide or ceramic tools	Provides superior wear resistance and extended tool life.
Geometry	Positive rake, sharp edges	Improves chip flow and ensures smoother surface finishes.
Cutting Speed	150–250 m/min	Reduces heat generation and prevents material deformation.
Feed Rate	0.10–0.20 mm/rev	Ensures smooth cutting and minimizes burr formation.
Coolant	Flood coolant or air blast	Reduces heat and enhances surface finish.

Brass C655 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	25–35
Finishing	200–250	0.05–0.10	0.5–1.0	30–50

Typical Machining Methods for Brass C655

Machining Process	Function and Benefit for Brass C655
CNC Machining	Ideal for high-speed, precision machining of parts like connectors and bushings used in industrial and automotive applications.
CNC Milling	Suitable for creating slots, grooves, and complex shapes in components such as valves, fittings, and other industrial parts.
CNC Turning	Used for turning cylindrical parts like bushings, gears, and mechanical components in automotive and industrial machinery.
CNC Drilling	Ideal for creating precise holes for fasteners and mechanical parts, used in automotive and industrial applications.
CNC Boring	Ensures precision internal machining for parts such as bearings and bushings.
CNC Grinding	Provides smooth finishes for parts exposed to wear and tear, such as gears and shafts.
Multi-Axis Machining	Ideal for producing complex, multi-featured parts in industries such as aerospace and automotive.
Precision Machining	Provides ultra-tight tolerances for high-performance components in industries like medical devices and aerospace.
EDM Machining	Used for creating intricate features and fine details in parts like connectors and switches for automotive and industrial uses.

Surface Treatment for Brass C655 CNC Parts

Electroplating: Enhances corrosion resistance and provides a shiny finish for electrical connectors and other components.
Polishing: Achieves a high-gloss finish for decorative parts and improves functionality.
Brushing: Creates satin or matte finishes for components exposed to frequent handling.
PVD Coating: Adds a durable coating that increases wear resistance and extends the part's life.
Passivation: Improves corrosion resistance, especially for components exposed to chemicals.
Powder Coating: Provides a thick, protective finish ideal for parts exposed to UV light and harsh conditions.
Teflon Coating: Adds non-stick and chemical-resistant properties, which are ideal for mechanical applications.
Chrome Plating: Provides a glossy, durable coating that resists corrosion and enhances appearance.

Industry Applications of Brass C655

Aerospace Industry: Used for manufacturing components such as connectors, bushings, and fittings subjected to high stresses.
Electrical & Power: Ideal for electrical components that require high conductivity and durability, such as terminals and connectors.
Automotive Industry: Commonly used in automotive applications such as connectors, bushings, and fittings.
Plumbing Industry: Used in producing valves, fittings, and other components exposed to moisture.