Loctite 243 Medium Strength Threadlocker

The Loctite 243 Medium Strength Threadlocker is a blue, anaerobic threadlocker for locking and sealing fasteners that still need to come apart with standard hand tools. It cures between close-fitting metal threads to stop loosening and leakage from shock and vibration, giving 22 N·m breakaway torque on M10 bolts and handling -55°C to +180°C. It cures on stainless steel and plated parts as well as brass and copper, and tolerates light oil on as-received fasteners. Available in 10 ml and 50 ml.

Shake the bottle, clean and dry the threads, and apply a few drops at the nut engagement area, or to the lower third of a blind hole; fixture strength comes in about 10 minutes. Hand tools will usually undo it, with local heat to about 250°C as a fallback, and it isn't normally recommended for plastics or pure-oxygen systems. Consult the Safety Data Sheet before use.

At a glance

• Pumps and gearboxes — bolts needing routine service
• Electric motors — housing and mounting fasteners
• Vehicles and mobile plant — fasteners under vibration
• Stainless and plated fasteners — locking passive metals

Full specifications, applications, features and important limits are in the tabs below.