C87900 is a leaded tin-zinc bronze alloy, belonging to the copper-based casting alloy family. Its unique chemical composition—typically containing copper as the base element, with tin for strength, zinc for improved fluidity, and lead for machinability—gives it a balanced combination of mechanical and physical properties. The material exhibits moderate tensile strength, good hardness, and excellent anti-friction characteristics, which make it suitable for applications where sliding contact or light-to-medium loads are involved. Additionally, its castability and dimensional stability allow it to be produced in strip form with consistent quality for further processing.
Thanks to its superior machinability, C87900 copper strip is widely used in the manufacture of precision-engineered parts such as bushings, bearings, pump components, valve guides, and hydraulic fittings. Its wear resistance ensures prolonged service life under frictional conditions, while its corrosion resistance provides reliable performance in moist or mildly aggressive environments. Moreover, the alloy’s good thermal and electrical conductivity, though moderate compared to pure copper, remains adequate for many industrial uses. Overall, C87900 offers a cost-effective solution for engineers seeking a durable, easy-to-machine, and corrosion-resistant copper alloy strip for high-volume production.
| Property | Value / Range |
|---|---|
| Alloy Type | Leaded Tin-Zinc Bronze (Copper Alloy C87900) |
| UNS Number | C87900 |
| Cu (Copper) | 76.0 – 80.0% |
| Sn (Tin) | 3.0 – 5.0% |
| Zn (Zinc) | 10.0 – 14.0% |
| Pb (Lead) | 2.0 – 4.0% |
| Other Elements (total) | ≤ 0.50% |
| Thickness Range | 0.10 mm – 2.0 mm (customizable) |
| Width Range | 5 mm – 300 mm (customizable) |
| Temper / Hardness | Annealed (soft), 1/4 Hard, 1/2 Hard, Full Hard |
| Tensile Strength | 250 – 500 MPa (depends on temper) |
| Yield Strength (0.2% offset) | 120 – 350 MPa |
| Elongation (% in 50 mm) | 10 – 30% (depends on temper) |
| Hardness (HV) | 60 – 160 (depends on temper) |
| Density | ~8.7 g/cm³ |
| Electrical Conductivity | ~12 – 15% IACS |
| Thermal Conductivity | ~50 – 60 W/(m·K) |
| Melting Range | ~850 – 950 °C |
| Corrosion Resistance | Good (atmospheric & mild chemical) |
| Machinability Rating | 80% (vs. free-cutting brass C36000 = 100%) |
| Surface Finish | Mill finish, polished, or tin-plated (optional) |
| Edge Condition | Slit edge, deburred, or rounded edge |
| Typical Applications | Bushings, bearings, valve guides, pump parts, hydraulic fittings, precision wear components |
