LOCTITE^® 515 is a form-in-place anaerobic-curing flange sealant that cures when confined in the absence of air between close fitting metal surfaces. It seals close fitting joints between rigid metal faces and flanges and will flex with minor flange movements. It provides resistance to low pressures immediately after assembly of flanges, and is typically used as a form-in-place gasket for pumps, thermostats, compressors, transmission housing,s and axle covers. The product is fluorescent under UV light, allowing visual inspection of the bead.