Electricity transmission from source to consumers is achieved through overhead power lines. Under the influence of weather conditions, additional stress is generated and may lead to accelerated deterioration and premature breakage. The analysis of stress and strain at wire level has a decisive role in identifying areas with peak loads and in network lifetime evaluation. The mechanical properties of the conductor may change with the emergence and development of contact imprints. In order to understand how an imprint develops and how it influences the properties of the conductor, imprint and tensile tests were done on wires taken from a steel-aluminum conductor. Theoretical and experimental researches have shown that the shape and size of imprints occurring at the contact points between wires have a significant influence on the tensile strength of the conductors. Additionally, local deformations can lead to the initiation and propagation of fretting fatigue cracks.