C87800 copper strip is a cast silicon brass alloy based on a copper-zinc matrix, with controlled additions of silicon and lead. Its chemical composition is optimized to deliver excellent machinability and moderate mechanical strength, making it suitable for corrosion-resistant components operating under moderate loads. The material is typically supplied in the as-cast condition or after simple machining, and is not recommended for cold stamping, bending, or deep-drawing operations due to its limited ductility.
C87800 copper strip is widely used in the production of valves, fittings, pump bodies, plumbing accessories, and instrument parts, particularly suited for high-volume automatic turning and drilling processes. Its good resistance to dezincification corrosion ensures reliable performance in potable water and industrial water systems. However, due to its low plasticity, designers should avoid complex deformed geometries and should allow sufficient machining allowances to guarantee final dimensional accuracy.
| Property | Value / Requirement |
|---|---|
| Material Designation | C87800 (UNS) / Cast Silicon Brass |
| Applicable Standard | ASTM B584 (for castings); strip references same composition |
| Copper (Cu) | 80.0% – 83.0% |
| Silicon (Si) | 3.5% – 4.3% |
| Zinc (Zn) | Remainder (approx. 12% – 16%) |
| Lead (Pb) | 0.15% – 0.35% |
| Tin (Sn) | ≤ 0.25% |
| Iron (Fe) | ≤ 0.15% |
| Other Impurities (Total) | ≤ 0.50% |
| Density | 8.33 g/cm³ |
| Melting Range | Approx. 850°C – 900°C |
| Thermal Conductivity | Approx. 85 W/(m·K) |
| Electrical Conductivity | Approx. 15% IACS |
| Tensile Strength (Typical) | 380 – 480 MPa (as-cast) |
| Yield Strength (0.2% Offset) | 170 – 240 MPa |
| Elongation (in 50 mm) | 5% – 10% (typical, varies with section size) |
| Hardness (Brinell) | 100 – 130 HB |
| Machinability Rating | 80% (vs. free-cutting brass C36000 = 100%) |
| Corrosion Resistance | Good resistance to dezincification and atmospheric/water corrosion |
| Formability | Poor; not recommended for cold bending, stamping, or deep drawing |
| Typical Applications | Valves, pipe fittings, pump bodies, plumbing components, instrument parts |
| Supply Form | Strip, sheet, or as-cast blanks for machining |
| Heat Treatment | Not heat-treatable; properties derived from as-cast condition |
