Abstract: The present invention relates to a copper alloy, in particular for components which carry media or drinking water, in particular fittings, valves or compression joints and also an advantageous use of the copper alloy and components for lines carrying media or drinking water. It is an object of the present invention to provide a copper alloy which has good corrosion resistance, good castability and mechanical workability and also good mechanical properties and displays good migration values, particularly in respect of the migration of lead and nickel ions into drinking water. The copper alloy provided for this purpose by the present invention comprises from 2% by weight to 4.5% by weight of silicon, from 1 to 15% by weight of zinc and from 0.05% by weight to 2% by weight of manganese. Furthermore, from 0.05 to 0.4% by weight of aluminium and from 0.05 to 2% by weight of tin can optionally be present. As balance, the copper alloy contains copper and unavoidable impurities.