Abstract: To prevent electric resistance between an electric conductor and a coupling part made of aluminum from becoming larger by stopping cold flow in an aluminum electric conductor, an end section of the aluminum electric conductor is crimped at a crimping section of the coupling part, multiple projections are formed in the crimping section, each of the projections has a truncated quadrangular pyramid shape and also has four inclined planes, the projections are pressed into the surface of the aluminum electric conductor but bases of the projections are not inserted, a distorted region is formed on the surface of the aluminum electric conductor along the inclined plane, thereby forming multiple independent regions, each surrounded by distorted regions, on the surface of the aluminum electric wire.