A coaxial connector assembly for interconnection with a coaxial cable with a solid outer conductor is provided with a monolithic connector body with a bore. A mating surface with a decreasing diameter toward a connector end is provided on an outer diameter of the connector body proximate the connector end. An overbody may be provided overmolded upon a cable end of the connector body. An interface end may be seated upon the mating surface, the interface end provided with a desired connection interface. The interface end may be permanently coupled to the mating surface by a molecular bond interconnection. In a method of interconnection, the interface end is coupled to the mating surface by application of radial ultrasonic welding.