Yellow Brass is a widely used copper–zinc alloy known for its bright gold-like appearance, excellent machinability, and good corrosion resistance. It typically contains 60–70% copper and 30–40% zinc.
Due to its superior formability, balanced strength, and attractive finish, yellow brass is extensively used in plumbing, electrical components, decorative items, and musical instruments. It is also commonly known as Cartridge Brass (C260).
Chemical Composition
| Element | Content (wt%) |
|---|---|
| Copper (Cu) | 60 – 70 |
| Zinc (Zn) | 30 – 35 |
| Lead (Pb) | 0 – 3 (machinability grades) |
| Iron (Fe) | ≤ 0.1 |
| Tin (Sn) | ≤ 1 |
| Other Impurities | Trace |
Note:
≤35% Zn → Primarily alpha phase
>35% Zn → Alpha–beta structure (stronger, less ductile)
Metallurgical Structure & Behavior
Phases: Alpha (α) or Alpha + Beta (α + β)
Alpha phase crystal structure: FCC
Beta phase crystal structure: BCC (harder, stronger)
Metallurgical nature: Substitutional solid solution
The dual-phase structure in higher-zinc grades improves strength and hot workability at the expense of ductility.
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 8.3 – 8.5 g/cm³ |
| Melting Range | 900 – 940 °C |
| Electrical Conductivity | 20 – 28% IACS |
| Thermal Conductivity | 110 – 125 W/m·K |
| Thermal Expansion | ~20 × 10⁻⁶ /°C |
| Color | Bright yellow to golden |
| Magnetic Behavior | Non-magnetic |
| Corrosion Resistance | Good |
Mechanical Properties
| Property | Typical Range |
|---|---|
| Tensile Strength | 300 – 600 MPa |
| Yield Strength | 120 – 450 MPa |
| Elongation | 10 – 45% |
| Hardness | 70 – 160 HB |
| Impact Toughness | Moderate |
Key Characteristics
✔ Bright decorative finish
✔ Balanced strength and ductility
✔ Good machinability (especially leaded grades)
✔ Good corrosion resistance
✔ Excellent electrical and thermal conductivity
Available Forms
| Form | Description |
|---|---|
| Rods & Bars | Machined parts, fasteners |
| Sheets & Plates | Panels, decorative uses |
| Tubes & Pipes | Plumbing, heat exchangers |
| Wires | Electrical components, springs |
| Castings | Valves, fittings |
| Forgings | Couplings, connectors |
Applications
Plumbing valves, faucets, and fittings
Electrical terminals and switch components
Bushings, gears, and connectors
Architectural hardware and decorative fittings
Musical instruments and consumer goods
Advantages
✔ Attractive appearance
✔ Good corrosion resistance
✔ Easy to fabricate and machine
✔ Versatile across industries
✔ Cost-effective copper alloy
Yellow Brass vs Red Brass
| Feature | Yellow Brass | Red Brass |
|---|---|---|
| Copper Content | 60 – 70% | 80 – 85% |
| Zinc Content | 30 – 35% | 5 – 15% |
| Strength | Higher | Moderate |
| Corrosion Resistance | Good | Excellent |
| Color | Bright yellow | Reddish-gold |
Why Choose Yellow Brass?
Yellow brass offers an excellent balance of strength, ductility, corrosion resistance, machinability, and visual appeal. Its adaptability across plumbing, electrical, mechanical, and decorative applications makes it one of the most commercially important brass alloys.