LOCTITE® 518™ Flange sealant Flexible, high-strength anaerobic gasketing material designed for use on rigid iron, aluminium and steel flanged mating surfaces. Fills gaps up to 0.25 mm and forms a flexible, chemical-resistant seal that will not tear or decay. Parts disassemble easily, even after extended service. Resists high pressure when fully cured. No compression set or misaligned gaskets. Easy to automate.