Loctite 222 242 272 243 262 271 270 290 threadlocker glue

Loctite threadlockers are anaerobic adhesives designed to prevent loosening, leakage, and corrosion on threaded fasteners by filling the gaps between threads and curing into a strong bond when deprived of air in contact with metal. Different grades offer varying levels of strength and removability: Loctite 222 (Purple) is low-strength, ideal for small-diameter or adjustment screws (e.g., set screws on carburetors or electronic devices) and removable with standard hand tools; Loctite 242 (Blue) is medium-strength, the most common general-purpose grade for applications like valve covers or oil pans, requiring hand tools for disassembly; Loctite 243 (Blue) is an oil-tolerant version of 242, suitable for surfaces with light oil contamination; and Loctite 271 (Red) is high-strength, designed for permanent locking on large bolts and studs, typically requiring heat to break the bond.