Loctite 242 Medium Strength Threadlocker Blue 250 mL Bottle — Removable, Vibration Resistant

Loctite 24241 Blue is a medium-strength anaerobic threadlocker in a 250 mL bottle designed to prevent fastener loosening while remaining service-removable with hand tools.

Engineered for general-purpose fastening, this Loctite 242 medium-strength formula cures in the absence of air and on metal surfaces to lock bolts and studs between 1/4" and 3/4" in diameter. It balances holding power with disassembly capability, tolerates temperatures from -65°F to 300°F, and reaches full cure in about 24 hours. The product arrives as a liquid with a mild odor, a specific gravity of 1.1, and a viscosity in the 1200–5000 cP range, supplied in a 250 mL bottle manufactured in the United States.

How does this threadlocker secure fasteners without making them permanent?

Loctite 24241 uses an anaerobic chemistry that remains liquid until confined between metal threads and deprived of air, at which point it polymerizes and forms a dependable bond. The medium strength formulation is engineered to resist shock and vibration while allowing removal with conventional hand tools, avoiding destructive disassembly methods.

• Best for fasteners 1/4" to 3/4" diameter
• Gap fill up to 0.005 inches for typical thread clearances
• Removable with hand tools—no heat or special solvents typically required

What are the cure time and environmental limits I should expect?

Initial handling strength begins within about 10 minutes after application, and full cure is normally achieved in roughly 24 hours under ideal conditions. The threadlocker maintains performance across a wide temperature window, making it suitable for many indoor and outdoor mechanical assemblies.

• Handling/set time: around 10 minutes
• Full cure: approximately 24 hours
• Service temperature range: -65°F to 300°F

How do I apply Loctite 24241 for reliable results?

Clean mating threads of oil, dirt, and rust before applying a few drops directly to the fastener threads. Assemble and tighten to specification; excess can be wiped away. Using the correct amount—enough to wet the threads but not so much that it runs—helps ensure consistent curing and performance.

• Recommended application temperature around 72°F for best flow and cure
• Use on metal-to-metal threaded connections only
• Apply to clean, dry threads and tighten per torque specs

What physical properties and safety considerations should I note?

The product is a low-odor liquid with a specific gravity of about 1.1 and a moderate viscosity range (1200–5000 cP), packaged in a 250 mL bottle. It has a flash point above 93.3°C; standard precautions for adhesives and sealants apply—avoid skin and eye contact and follow the manufacturer's safety data sheet for handling and disposal.

• Form: liquid; container size: 250 mL bottle
• Flash point: greater than 93.3°C (safe handling recommended)
• Manufactured in the United States by Loctite

Who is this for? Technicians, maintenance crews, and DIYers who need a dependable, medium-strength threadlocker that prevents loosening from vibration yet allows future disassembly will find Loctite 24241 well suited to mechanical repairs, automotive fasteners, industrial equipment maintenance, and general-purpose assemblies. Choose this product when you want a balance of secure locking and practical removability in a professional-grade 250 mL bottle.