ahi, kus metallide jt materjalide sulatamiseks kasutatakse elektrikaare soojust; eristatakse otsetoime- ja kaudtoimekaarahje (vt otsetoimekaarahi; kaudtoimekaarahi), a furnace in which metal is melted either directly by an electric arc between an electrode and the work or indirectly by an arc between two electrodes adjacent to the metal (see: direct-arc furnace; indirect-arc furnace)