Loctite 640 is a green, anaerobic, low viscosity, methacrylate ester-based retaining compound ideal for parts requiring a longer positioning time. Fixturing time on steel is 2 h. Also used for active metals such as brass. This is a high strength product with good temperature resistance. Max. diametrical clearance is 0.1 mm and service temperature is -55 to +175°C. Fluorescence allows product presence to be monitored.