LOCTITE 241 Medium-Strength Low-Viscosity Threadlocker for M12 Metal Fasteners

LOCTITE 241 Threadlocker Benefits

LOCTITE 241 Threadlocker provides dependable medium-strength retention for small threaded fasteners without creating a permanently locked assembly. This balance makes it useful for machinery and equipment that require vibration resistance but may still need periodic adjustment, inspection or component replacement.

The low-viscosity liquid spreads effectively through narrow thread clearances, helping fill microscopic spaces between male and female threads. Once cured, it creates a continuous polymer layer that helps distribute loads, seal the thread path and limit the entry of moisture or corrosive contamination.

The one-component format requires no resin-to-hardener mixing, reducing preparation time and application errors. Positive fluorescence under ultraviolet light also allows production teams to verify product presence and application coverage with suitable UV inspection equipment.

LOCTITE 241 Threadlocker Applications

LOCTITE 241 Threadlocker is formulated for small threaded fasteners up to M12. Typical applications include mounting bolts, housing screws, adjustment fasteners, motor components, electrical machinery, pumps, gearboxes, appliances, machine tools and general industrial equipment.

The product is suitable for steel, brass and stainless-steel fasteners. Henkel specifically identifies it as useful on less-active substrates such as stainless steel and coated surfaces, including zinc-plated and zinc-flake finishes, where standard hand-tool disassembly is required for maintenance.

It can be used on through-hole and blind-hole assemblies, as well as selected threaded sealing applications. The adhesive is intended primarily for metallic components. Plastics, particularly stress-sensitive thermoplastics, should be tested carefully because anaerobic materials may contribute to stress cracking.

LOCTITE 241 Threadlocker Technical Properties

LOCTITE 241 Threadlocker is an opaque blue methacrylate-ester liquid with a typical specific gravity of approximately 1.06 at 25°C. Henkel publishes a low viscosity range of approximately 110 to 150 mPa·s, supporting penetration and complete wetting of close-fitting small threads.

After 24 hours of curing at 22°C, typical performance on M10 steel nuts and bolts includes breakaway torque of approximately 11.5 N·m and prevailing torque of approximately 10 N·m. Published static shear strength on steel pins and collars is approximately 10 MPa.

Cure speed varies according to substrate activity, thread clearance and ambient temperature. The current Henkel product page lists fixture times ranging from approximately 12 to 240 minutes across different conditions. Stainless steel, plated metals, low temperatures and larger thread clearances generally cure more slowly than active metals.

Laboratory testing demonstrates resistance to motor oil, unleaded gasoline, ethanol, brake fluid and water-glycol mixtures under specified exposure conditions. These figures are typical technical data rather than guaranteed purchasing specifications, so the actual fastener, finish and operating environment should be validated.

How to Apply LOCTITE 241 Threadlocker

Clean the internal and external threads with a compatible LOCTITE cleaner and allow them to dry completely. When the substrate is inactive or curing is unacceptably slow, apply LOCTITE SF 7649 or LOCTITE SF 7471 Activator and allow the solvent carrier to evaporate.

For through-hole assemblies, apply several drops to the bolt around the nut-engagement area. For blind holes, dispense the adhesive into the lower section of the internal threads. Assemble the parts and tighten them to the specified torque before fixture strength develops.

Standard hand tools are normally sufficient for disassembly. In unusual assemblies with excessive engagement length, localized heating to approximately 250°C may assist removal. Store unopened packaging in a dry location, ideally between 8°C and 21°C.

Why Choose LOCTITE 241 Threadlocker?

LOCTITE 241 Threadlocker combines low-viscosity penetration, medium-strength locking, UV inspection and convenient maintenance removal. It is a practical solution for securing small steel, brass, stainless-steel and coated fasteners exposed to vibration and shock.

Review the official Henkel LOCTITE 241 Technical Data Sheet before qualification or production use. Explore our medium-strength threadlockers for additional removable fastener-locking solutions.