518 flange sealant cures when confined in the absence of air between close-fitting metal surfaces. It is an anaerobic gasketing material designed for use on rigid iron, aluminum, and steel flanged mating surfaces. LOCTITE 518 fills gaps up to 0.25mm and forms a flexible, chemical-resistant seal that will not tear or decay. Parts disassemble easily, even after extended service. Typical applications include sealing close-fitting joints between rigid metal faces and flanges. It is also used as a formed-in-place gasket on rigid flanged connections, e.g. transmissions and motor housings.