1. Chemical Composition (ASTM Standards)
| Element | C28000 (Muntz Metal) | C22000 (Commercial Bronze/Red Brass) | Key Impact on Trade & Performance |
|---|---|---|---|
| Copper (Cu) | 57.0 – 60.0% | 78.0 – 82.0% | C22000's higher Cu content enhances corrosion resistance (critical for plumbing/marine use); C28000's lower Cu content reduces cost. |
| Zinc (Zn) | 38.0 – 41.0% | 18.0 – 22.0% | C28000's higher Zn content improves strength/hardness (for structural parts); C22000's lower Zn minimizes dezincification risk. |
| Lead (Pb) | ≤0.07% (unleaded) | ≤0.05% (unleaded) | Both meet environmental standards (RoHS/EPA), but lead-free composition is mandatory for food/water-contact applications. |
| Iron (Fe) | ≤0.10% | ≤0.10% | Trace impurity; no major impact on trade suitability. |
| Other Elements | ≤0.30% (total) | ≤0.30% (total) | Strict control required for compliance with industrial standards. |
Trade Note: Customers often specify Cu/Zn ratios for targeted performance-e.g., high Cu for corrosion resistance (C22000) or cost-effectiveness (C28000) for non-critical structural parts.
2. Core Mechanical & Physical Properties
| Property | C28000 (Muntz Metal) | C22000 (Commercial Bronze/Red Brass) |
|---|---|---|
| Tensile Strength | 415 – 550 MPa (annealed) | 310 – 415 MPa (annealed) |
| Hardness (HB) | 100 – 140 (annealed) | 65 – 95 (annealed) |
| Ductility (% Elongation) | 20 – 30% (annealed) | 35 – 45% (annealed) |
| Corrosion Resistance | Moderate (resists atmospheric/freshwater corrosion; poor dezincification resistance). Not suitable for seawater or chlorinated water. | Excellent (resists dezincification, seawater, and chlorinated water). Ideal for harsh environments. |
| Thermal Conductivity | 110 W/m·K | 220 W/m·K |
| Machinability | Good (requires lubrication to avoid galling) | Very Good (excellent for machining and threading) |
3. Typical Applications (Trade-Focused)
| C28000 (Muntz Metal) | C22000 (Commercial Bronze/Red Brass) |
|---|---|
| - Structural tubes/pipes (industrial framing, handrails) | - Plumbing systems (potable water pipes, fittings, valve stems) |
| - Marine hull plates, ship decks (non-submerged parts) | - Marine hardware (submerged fittings, fasteners, boat components) |
| - Architectural cladding, decorative panels (cost-effective alternative to C22000) | - Decorative metalwork (door handles, railings, signage) |
| - Industrial components (conveyor rollers, machine parts) | - Heat exchangers, condenser tubes (moderate-temperature applications) |
| - Low-cost fasteners for non-corrosive environments | - Electrical connectors (low-voltage, corrosion-prone settings) |
