An inflator comprising a housing having an integrally formed mounting flange adapted to be heat-sealed directly to an inflatable article. A sleeve is injection molded in-situ inside the housing in which a pierce pin assembly is reciprocatably mounted within a central bore thereof. The sleeve within the housing allows the wall thickness of the housing to be significantly reduced and assures that the escaping gas from the cylinder always contacts the housing material. The sleeve includes a skirt extension with a socket defining the blind hole for receiving the end of the pivot pin of the firing lever to allow the injection-molding of a blind hole for the pivot pin without the need for subsequent drilling of the hole.
