Loctite 243 is a next-generation medium-strength, blue threadlocker designed for use on oily, contaminated, or “as-received” fasteners. It combines the vibration resistance of 242 with advanced oil tolerance, making it suitable for less-than-perfect assembly conditions. LOCTITE® 243 is a general purpose, medium viscosity, anaerobic-curing threadlocking adhesive. It is thixotropic to prevent migration after application, and is perfect for fasteners requiring normal disassembly with standard hand tools.