C28000

C28000 is a yellow brass alloy also known as Muntz Metal or CuZn40, containing approximately 60-63% copper and 36-41% zinc with limited amounts of lead and iron for machinability and strength.

Chemical Composition

• Copper (Cu): 59.00% – 63.00%

• Zinc (Zn): 36.30% – 41.00%

• Lead (Pb): 0.00% – 0.30%

• Iron (Fe): 0.00% – 0.07%

• Residuals (other elements): Up to 0.30%

Mechanical Properties

• Tensile Strength: 400 – 485 MPa

• Elongation: Typically up to 25%

• Hardness: Approximately 52 – 80 HRB (varies by shape and size)

Physical Properties

• Density: 8.39 g/cm³

• Melting Point: Solidus at 1650°F, Liquidus at 1660°F

• Electrical Conductivity: Around 28% IACS (International Annealed Copper Standard)

• Thermal Conductivity: ~71 BTU/sq ft/ft/hr/°F

• Coefficient of Thermal Expansion: 11.6 x 10⁻⁶/°F

Fabrication and Machinability

• Excellent soldering and brazing capabilities

• Good oxyacetylene welding; Fair gas shielded arc welding

• Not recommended for coated metal arc welding and seam welding

• Fair spot and butt weld capacity

• Cold working capacity is fair; hot forming capacity is excellent

• Forgeability rating about 90

• Machinability rating about 40% relative to free-cutting brass

Typical Applications

• Architectural components and builders' hardware

• Fasteners, industrial parts, and machine components

• Plumbing parts, valves, and fittings

• Decorative applications needing good mechanical strength and corrosion resistance