Copper in architecture used in residential and commercial building structures. Variations in color stem primarily from differences in the alloy chemical composition. Some of the more popular copper alloys and their associated Unified Numbering System (UNS) numbers developed by ASTM and SAE are as follows: In practice, the term ‘bronze’ may be used for a variety of copper alloys with little or no tin if they resemble true bronzes in color. Further information on architectural copper alloys is available. The criteria by which copper and copper alloys are selected for architectural projects include color, strength, hardness, resistance to fatigue and corrosion, electrical and
Copper conductor alloys are offset by their lower electrical conductivities. Design engineers weigh the advantages and disadvantages of the various types of copper and copper alloy conductors when determining which type to specify for a specific electrical application. An example of a copper alloy conductor is cadmium copper wire, which is used for railroad electrification in North America. In Britain the BPO (later Post Office Telecommunications) used cadmium copper aerial lines with 1% cadmium for extra strength; for local lines 40 lb/mile (1.3 mm dia) and for toll lines 70 lb/mile (1.7 mm dia). Some of the major application markets for copper