Copper-zinc alloys are widely used as contact carrier materials in switching devices for electrical power engineering because of their high electrical conductivity, the higher mechanical strength combined with good formability compared to pure copper ''<xr id="tab:tab5.7"/> (Tables Tab. 5.7 ) and <xr id="tab:tab5.8"/> (Tab. 5.8)'', and at the same time their reasonable economic costs. Especially suitable are the brasses with up to 37 wt% Zn content which are according to the phase diagram all made up from the " -phase of the CuZn system <xr id="fig:Phase diagram of copper-zinc for the range of 0-60 wt% zinc"/>(Fig. 5.5). It is important to note the strong dependence of the electrical conductivity and mechanical strength on the zinc content <xr id="fig:Mechanical properties of brass depending on the copper content (after cold working of 0 and 50%)"/>(Fig. 5.6).  <figtable id="tab:tab5.7">'''Table 5.7: Physical Properties of Selected Copper-Zinc Alloys'''  {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material/<br />Designation<br />EN UNS !Composition<br />[wt%]!Density<br />[g/cm³]!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[MS/m] [% IACS] !Electrical<br />Resistivity<br />[μΩ·cm]!Thermal<br />Conductivity<br />[W/(m·K)]!Coeff. of Linear<br />Thermal<br />Expansion<br />[10^-6/K]!Modulus of<br />Elasticity<br />[GPa]!Softening Temperature<br />(approx. 10% loss in<br />strength)<br />[°C]!Melting<br />Temp Range<br />[°C]|-|CuZn5<br />CW500L<br />C21000|Cu 94 - 96<br />Zn Rest|8.87|33|57|3.8|243|18.0|127||1055 - 1065|}</figtable>  <figtable id="tab:tab5.8">'''Table 5.8: Mechanical Properties of Selected Copper-Zinc Alloys''' {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Hardness<br />Condition!Tensile Strength R_m<br />[MPa]!0,2% YieldStrength<br />R_p02<br />[MPa]!Elongation<br />A₅₀<br />[%]!Vickers<br />Hardness<br />HV!Bend Radius¹⁾<br />perpendicular to<br />rolling direction!Bend Radius¹⁾<br />parallel to<br />rolling direction!Spring Bending<br />Limit FFB<br />[MPa]!Spring Fatigue<br />Limit FBW<br />[MPa]|-|CuAg0,10|R 200<br />R 360|200 - 250<br />360|120<br />320|> 40<br />> 3|40<br />90|0 x t<br />0.5 x t|0 x t<br />0.5 x t|240|120|-|CuFe0,1P|R 300<br />R 360<br />R 420|300 - 380<br />360 - 440<br />420 - 500|> 260<br />> 300<br />> 350|> 10<br />> 3<br />> 2|80 - 110<br />110 - 130<br />120 - 150|0 x t<br />0.5 x t<br />1.5 x t|0 x t<br />0.5 x t<br />1.5 x t|250|160|-|CuSn0,15|R 250<br />R 300<br />R 360<br />R 420|250 - 320<br />300 - 370<br />360 - 430<br />420 - 490|> 200<br />> 250<br />> 300<br />> 350|> 9<br />> 4<br />> 3<br />> 2|60 - 90<br />85 - 110<br />105 - 130<br />120 - 140|0 x t<br />0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />0 x t<br />1 x t|250|160|-|CuFe2P|R 370<br />R 420<br />R 470<br />R 520|370 - 430<br />420 - 480<br />470 - 530<br />520 - 580|> 300<br />> 380<br />> 430<br />> 470|> 6<br />> 4<br />> 4<br />> 3|115 - 135<br />130 - 150<br />140 - 160<br />150 - 170|0 x t<br />0.5 x t<br />0.5 x t<br />1 x t|0 x t<br />0.5 x t<br />0.5 x t<br />1 x t|340|200|-|CuNi2Si|R 430²⁾<br />R 510²⁾<br />R 600²⁾|430 - 520<br />510 - 600<br />600 - 680|> 350<br />> 450<br />> 550|> 10<br />> 7<br />> 5|125 - 155<br />150 - 180<br />180 - 210|0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />1 x t|500|230|-|CuSn1CrNiTi|R 450<br />R 540<br />R 620|450 - 550<br />540 - 620<br />620 - 700|> 350<br />> 450<br />> 520|> 9<br />> 6<br />> 3|130 - 170<br />160 - 200<br />180 - 220|0.5 x t<br />1 x t<br />3 x t|0.5 x t<br />2 x t<br />6 x t|530|250|-|CuNi1Co1Si|R 800<br />R 850|> 800<br />> 850|> 760<br />> 830|> 4<br />> 1|> 260<br />> 275|0.5 x t<br />1.5 x t|1.5 x t<br />2.5 x t|||-|CuCrSiTi|R 400<br />R 460<br />R 530|400 - 480<br />460 - 540<br />530 - 610|> 300<br />> 370<br />> 460|> 8<br />> 5<br />> 2|120 - 150<br />140 - 170<br />150 - 190|0 x t<br />0.5 x t<br />1 x t|0 x t<br />0.5 x t<br />1 x t|400|220|}</figtable>