Glass Sealing 27 is a ductile 28% chromium-iron alloy used for glass-to-metal seals in special electronic and vacuum tubes and in incandescent and fluorescent lamps. It exhibits no phase transformation up to 2100°F (1150°C) and is particularly adapted to outside sealing, such as caps where it has the advantage of gripping the glass on cooling, thus increasing the tightness of the seal. Annealed strip can be used for many cold drawn shapes.
