I was recently asked by a copper wire manufacturer if anyone is using less than EPT grade copper for wire used in electrical conductivity. Is anyone aware of this? It was suggested that this was imported copper.
Electrical wire and cable specifications disallow the use of copper with conductivity less than that for annealed Electrolytic Tough Pitch Copper (ETP). See specifications CDA 110 ETP Copper, ASTM B 187, and ASTM B 152 copper. If hard copper is utilized as in the case in a very few circumstances, the electrical conductivity is 97% of the annealed Electrolytic Tough Pitch Copper (ETP) conductivity but regardless it is still ETP copper.