Gunmetal – multi-constituent bronze

CuSn3Zn8Pb5-C - GS

Standard designation
Classification in accordance with DIN EN 1982 CuSn3Zn8Pb5-C - GS
Material number in accordance with DIN EN 1982 CC490K
Old classification in accordance with DIN 1705 and DIN 1716 G-CuSn2ZnPb
Old material no. 2.1098.01
Chemical composition in weight %
Copper Cu 81.0-86.0 (including nickel)
Nickel Ni < 0.2
Phosphorus P < 0.05
Lead Pb 3.0-6.0
Tin Sn 2.0-3.5
Aluminium Al < 0.01
Iron Fe < 0.5
Sulphur S < 0.10
Antimony Sb < 0.30
Silicon Si < 0.01
Zinc Zn 7.0-9.5
Physical properties
Density g/cm³ 8.7
Melting range °C 830-1040
Amount of shrinkage °C 1.3-1.5
electr. conductivity at 20°C MS/m 8.5
Thermal conductivity at 20°C W/(m*K) 71
Linear thermal expansion coefficient 10-6/K 18.0
Mechanical properties
Tensile strength Rm (MPa) 180
0.2% - yield strength RP 0.2 (MPa) 85
Elongation at break A (%) 15
Brinell hardness HB10 60
Technological properties
Elasticity modulus GPa 90-95
Flexural strength MPa 110
Shear strength MPa 155-170
Chip brazing and weldability
Machinability 1
Brazing medium
Gas welding poor
Inert gas welding poor
Comments
Medium-hard construction material, good for casting, corrosion-resistant in service water, also at elevated temperatures
Notes on use
The alloy is used specifically for thin-walled valves (up to 12 mm wall thickness), suitable up to 225°C