Abstract: A blow molding apparatus for expanding a polymer tube and a method for fabricating a stent using the apparatus is disclosed. The polymer tube is disposed within a tubular mold, over which a heated ring is made of a material having thermal conductivity greater than the tubular mold is translated. The ring is heated with heated fluid streams applied directly onto an outer surface of the ring, or heated fluid circulated within the ring, or an electrically resistive coil within the ring, or combinations thereof. The heated ring uniformly heats a circumference of the tubular mold that, in turn, uniformly heats a circumferential band of the polymer tube. The heated polymer tube is progressively expanded radially and axially while the ring is translated longitudinally over the polymer tube. The expanded polymer tube can be heat set and cooled prior to removal from the tubular mold.