One embodiment of a heated nozzle for extruding meltable material consists of an electrically conductive nozzle, comprised of an inlet, an outlet, and a passage connecting inlet and outlet. The nozzle fits into a hole or gap cut or formed through a loop of high permeability soft magnetic material such as ferrite or pressed iron powder. Electrically conductive wire is coiled around and through this magnetic loop to form a coil. A high-frequency alternating current is supplied to the coil, inducing a magnetic field in the magnetic core. The magnetic field, when passing through the electrically conductive nozzle, induces eddy currents that heat the nozzle to melt the material entering the inlet.