C87500 annealed copper sheet is produced through a controlled thermal treatment that fully recrystallizes the grain structure, resulting in a softened, stress-free condition with dramatically improved ductility and bendability. This annealing process reduces hardness and tensile strength compared to the cold-worked state, while preserving the alloy’s intrinsic high electrical and thermal conductivity. The material exhibits uniform microstructure, excellent dimensional stability, and low springback, making it highly predictable during secondary forming operations such as stamping, spinning, and hydroforming.
Thanks to its combination of formability, conductivity, and corrosion resistance, C87500 annealed copper sheet is widely used in electrical busbars, heat exchangers, decorative architectural panels, and automotive cooling systems. Its softened state allows for intricate geometries with tight radii without risk of edge cracking, reducing scrap rates and tooling wear in high-volume production. Additionally, the alloy’s resistance to tarnishing and atmospheric oxidation ensures reliable service life in both indoor and outdoor environments, while its consistent annealed temper provides uniform response to subsequent joining processes like soldering, brazing, and welding.
| Parameter | Value / Range |
|---|---|
| UNS Number | C87500 |
| Material Type | Cast Copper Alloy (Silicon Brass) |
| Common Forms | Sand casting, centrifugal casting, investment casting |
| Copper (Cu) | 79.0% – 82.0% |
| Silicon (Si) | 3.0% – 4.0% |
| Zinc (Zn) | Remainder |
| Lead (Pb) | ≤ 0.09% max |
| Iron (Fe) | ≤ 0.15% max |
| Tensile Strength (Typical) | 60 – 75 ksi (414 – 517 MPa) |
| Yield Strength (0.2% offset) | 30 – 40 ksi (207 – 276 MPa) |
| Elongation (in 2″) | 15% – 25% |
| Hardness (Brinell, 3000 kg) | 130 – 170 HB |
| Electrical Conductivity | ~6% – 7% IACS |
| Thermal Conductivity | ~26 – 30 W/m·K |
| Density | 0.300 lb/in³ (8.3 g/cm³) |
| Melting Range (Liquidus) | ~1710°F (~932°C) |
| Melting Range (Solidus) | ~1610°F (~877°C) |
| Machinability Rating | 60% (relative to C36000 = 100%) |
| Corrosion Resistance | Good resistance to atmospheric and seawater corrosion |
| Typical Applications | Valve bodies, pipe fittings, pump housings, impellers, marine hardware, decorative architectural castings |
