Aug 20 2012
Topics Covered
IntroductionChemical
CompositionPhysical PropertiesMechanical PropertiesThermal propertiesOther DesignationsFabrication and Heat
Treatment Machinability Welding
Introduction
UNS C85700 is an alloy of copper-zinc-lead which belongs to the cast
category. The presence of lead in the leaded yellow brass – copper casting alloy
offers it high machinability, strength and corrosion resistance. Lead behaves as
a lubricant and microscopic chip breaker.
The following datasheet provides chemical composition and properties
of UNS C85700.
Chemical Composition
The chemical composition of UNS C85700 copper alloy is given in the
following table.
| Element |
Content
(%) |
| Copper, Cu |
58.0-64.0 |
| Zinc, Zn |
32.0-40.0 |
| Lead, Pb |
0.80-1.50 |
| Tin, Sn |
0.50-1.50 |
| Nickel, Ni |
≤1.0 |
| Iron, Fe |
≤0.70 |
| Aluminium, Al |
≤0.55 |
| Silicon |
≤0.05 |
Physical Properties
The following table details the physical properties of UNS C85700.
| Properties |
Metric |
Imperial |
| Density |
8.41 g/cc |
0.304 lb/in³ |
Mechanical Properties
The mechanical properties of UNS C85700 copper alloy are shown in the
following table.
| Properties |
Metric |
Imperial |
| Elastic modulus |
117 GPa |
16969 ksi |
| Poisson's ratio |
0.34 |
0.34 |
| Hardness, Brinell |
75 |
75 |
| Tensile strength |
345 MPa |
50000 psi |
| Yield strength |
125 MPa |
18100 psi |
| Elongation at break |
40% |
40% |
| Machinability |
80 |
80 |
Thermal properties
The following table discusses the thermal properties of UNS C85700.
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient
(@20-260°C/68-500°F) |
22.0 µm/m°C |
12.2 µin/in°F |
| Thermal conductivity (@20°C/68°F) |
83.9 W/mK |
582 BTUin/hr.ft².°F |
Other Designations
Equivalent designations to UNS C85700 copper alloy include:
- ASTM B176
- ASTM B271
- ASTM B30
- ASTM B584
- ASTM B763
- QQ C390
Fabrication and Heat Treatment
Machinability
UNS C85700 has a machinability rating of 80.
Welding
The preferred welding techniques for UNS C85700 copper alloy are
soldering and brazing. Oxyacetylene welding, gas shielded arc welding, coated
metal arc welding and carbon arc welding are not recommended for this alloy.