LOCTITE® 243™ Blue Threadlocker 50ml – Medium Strength

LOCTITE® 243™ Threadlocker is a blue, medium-strength anaerobic adhesive designed to lock and seal threaded metal fasteners. It helps prevent nuts and bolts from loosening because of shock, vibration and operating conditions while still allowing normal disassembly with standard hand tools.

The 50 ml bottle is a practical size for maintenance departments, workshops, automotive applications, machinery servicing and industrial assembly operations.

Henkel classifies LOCTITE 243 as a general-purpose, medium-strength threadlocker with oil-tolerant and primerless characteristics. It is designed to work on a wide range of metal substrates, including passive metals such as stainless steel, aluminium and plated surfaces.

LOCTITE 243 Threadlocker for Metal Fasteners

LOCTITE 243 Threadlocker is formulated for threaded fasteners that require reliable locking but may need to be removed later for maintenance or servicing.

When applied between closely fitting metal threads, the anaerobic adhesive cures in the absence of air. The cured material helps prevent the threaded connection from loosening under vibration and shock while also helping seal the threaded assembly.

This makes LOCTITE 243 suitable for a wide variety of industrial fastening applications.

Medium-Strength Blue Threadlocker

LOCTITE 243 is classified as a medium-strength threadlocker. Its blue color provides easy visual identification during assembly and maintenance.

Unlike permanent high-strength threadlockers, the medium-strength formulation is designed to permit normal disassembly using standard hand tools. This makes it particularly useful for equipment that may require periodic servicing, adjustment or component replacement.

Henkel reports an approximate breakaway torque of 26 N·m on M10 steel nuts and bolts under its specified test conditions.

Oil-Tolerant and Primerless Formulation

One of the major advantages of LOCTITE 243 Threadlocker is its ability to tolerate residual oil and cutting fluids.

Henkel states that the product cures through most corrosion-prevention oils and cutting fluids on “as-received” fasteners without aggressive cleaning. It also works on passive metal substrates without primer.

This can simplify maintenance and assembly operations where completely oil-free preparation of every fastener is difficult.

However, surfaces should still be appropriately prepared according to the application and Henkel’s technical instructions. Excessive contamination, loose dirt or incompatible materials can affect bonding performance.

Anaerobic Curing Technology

LOCTITE 243 uses an anaerobic curing mechanism. The liquid remains workable while exposed to air but cures when confined between close-fitting metal surfaces where oxygen is excluded.

The product is a one-component adhesive and does not require mixing before application. Henkel’s technical data sheet identifies its technology as acrylic and its chemical type as dimethacrylate ester.

The stated fixture time is approximately 10 minutes, although actual cure speed can vary depending on factors such as temperature, gap size, substrate material and surface condition.

Temperature Resistance

LOCTITE 243 is specified for an application temperature range of approximately -55°C to 180°C.

This broad temperature range allows the threadlocker to be used in many automotive, machinery and industrial maintenance applications where threaded assemblies experience changing operating temperatures.

Always check the Henkel technical documentation for the specific application when operating near the limits of the stated temperature range.

Automotive and Machinery Applications

LOCTITE 243 Threadlocker can be used for many metal fastening applications, including:

• Automotive fasteners
• Machinery assembly
• Pumps
• Gearboxes
• Presses
• Electric motors
• Industrial equipment
• Maintenance and repair
• Mechanical assemblies
• General metal fastening

Henkel specifically highlights prevention of fastener loosening in vibrating assemblies such as pumps, gearboxes and presses.

Suitable Metal Substrates

LOCTITE 243 is designed for metal-to-metal threaded assemblies and can be used on both active and passive metals.

Henkel specifically identifies compatibility with:

• Steel
• Stainless steel
• Aluminium
• Plated metal surfaces

Its primerless performance on passive metals is particularly useful for maintenance and industrial assembly applications.

50 ml Bottle

This product is supplied in a 50 ml bottle, making it suitable for professional workshops and maintenance teams that need more product than a small consumer-size package while not requiring a large industrial container.

Henkel currently lists a 50 ml bottle configuration for LOCTITE 243.

Why Choose LOCTITE 243?

LOCTITE 243 Threadlocker combines medium-strength locking performance, oil tolerance and easy serviceability in one anaerobic formulation.

Its ability to work on passive metals without primer, together with its resistance to loosening caused by vibration and its removable nature, makes it a versatile choice for industrial maintenance and mechanical assembly.

The blue formulation also makes the product easy to identify during assembly and inspection.

Buy LOCTITE 243 Threadlocker 50ml

If you need LOCTITE 243 Threadlocker 50ml for automotive maintenance, machinery assembly or industrial fastening, verify the required application, substrate and operating conditions before use.

For industrial procurement, bulk requirements and commercial enquiries, contact Technosteer Online for availability and quotation.