An induction heater includes an electrically conductive coil that produces an alternating magnetic field when current is applied to the coil. The magnetic field is used to heat metal containers such as tubular containers. The coil extends about a heating path of travel that extends along the longitudinal axis of the coil. A transport device is provided to move the container through the magnetic field such that the longitudinal axis of the container is generally perpendicular to the longitudinal axis of the coil. This allows for heating the container at the twelve and six o'clock positions. The transport device functions to roll the container along the heating path. In a preferred embodiment, the coil is wrapped about a core with a generally rectangular shape. Ferromagnetic members may optionally be used to further shape the magnetic field. The methods and apparatus may be used for regular or irregularly shaped containers.