Sealing
6 A machine called a press seal is used to hermetically seal the mount inside the bulb. The mount is inserted into the bulb and both parts held securely. The bottom portion of the bulb is then heated to around 3,272°F (1,800°C) using gas/oxygen burners to soften the quartz. Stainless steel press pads, operating at pressures of 20-60 psi, press the quartz to the molybdenum foils forming the hermetic seal. During this operation, the bulb is being flushed with an inert gas (nitrogen or argon) to remove the air and prevent the mount from oxidizing. The outerleads protrude from the end of the press and provide a means to electrically connect the lamp to the lamp base.