A transcranial magnetic stimulation induction coil device (“TMS coil device”) is manufactured to contain coil windings of a predetermined size and shape and fixedly positioned at a predetermined location within and orientation in relation to a casing of the TMS coil device. In one embodiment, the coil windings are encased in a casting at a predetermined location within and orientation in relation to the casting, and the casting is fixedly positioned at a predetermined location within and orientation in relation to the casing. The size and shape of the coil windings and the casing within, and the location and orientation of the coil windings in relation to each other and the casing of, the TMS coil device are known with a high level of precision, such that navigated brain stimulation can be performed with the TMS coil device with a high degree of accuracy. In another embodiment, the TMS coil device defines a space interposed between the coil windings and the casing and containing a gas which absorbs heat energy generated at the coil windings, thereby reducing the rate of transfer of heat energy from the coil windings to the casing during operation of the TMS coil device.