A coaxial connector for interconnection with a coaxial cable with a solid outer conductor by ultrasonic welding is provided with a monolithic connector body with a bore. An annular flare seat is angled radially outward from the bore toward a connector end of the connector, the annular flare seat open to the connector end of the connector. An inner conductor cap is provided for interconnection with an inner conductor of the coaxial cable by ultrasonic welding. The ultrasonic welding of each of the inner and outer conductor interconnections may be performed via inner conductor and outer conductor sonotrodes which are coaxial with one another, without requiring the cable and or connector to be removed from their fixture.