Abstract: The electric contact is always made of silver and graphite, the electric conductivity of contact materials decreases as the graphite content increased. The hardness of silver-graphite is low, for example, the hardness of the 3wt% graphite-silver is HB 24.5-39.8MPa, and the electric conductivity is 72% IACS. The present work reports the similarity of electric conductivity for the 3wt% short carbon fibre-Ag composite and 3wt% graphite-silver. However, the hardness of the short carbon fiber-Ag composite is two times harder than that of graphite-silver. The specific gravity of graphite is 2.2 g/cm3, and that of carbon fibre is 1.75 g/cm3, so the 3wt% short carbon fibre-Ag composite contact will still save 5-7%Ag. The electric life of Ag-carbon fibre is much higher than silver-graphite at the same Ag contact.

Key words: carbon fibre, silver-graphite, electric contact