Loctite 242 - Threadlocker - 50ml

LOCTITE® 242 is a blue, medium-strength, medium-viscosity anaerobic threadlocking adhesive designed for securing and sealing threaded metal fasteners. It is a general-purpose threadlocker intended for applications where reliable resistance to vibration and loosening is required, while allowing the fastener to be removed with standard hand tools during servicing. 

LOCTITE 242 is thixotropic, meaning it has a formulation that helps reduce unwanted migration after application. It cures when confined between close-fitting metal threads in the absence of air, forming a strong bond that helps prevent nuts, bolts and threaded fasteners from loosening under vibration and normal operating loads. 

Key Features

Medium-strength threadlocker

Blue colour

Medium viscosity

Anaerobic curing technology

Thixotropic formulation

Designed for metal threaded fasteners

Helps prevent loosening caused by vibration

Allows normal disassembly using standard hand tools

Suitable for thread sizes up to M36

Fast fixture

Suitable for steel, stainless steel and brass

Available in several package sizes, including 50 ml and 250 ml bottles. 

Applications

LOCTITE 242 is suitable for a wide range of industrial and mechanical applications, including:

Nuts and bolts

Pumps and valves

Electric motors

Gearboxes

Machinery and equipment

Automotive assemblies

Industrial machinery

Flanged and threaded assemblies

General maintenance and repair applications

Fasteners subject to vibration

It is particularly useful where a threaded connection needs to remain secure during operation but may need to be disassembled later for maintenance. 

How LOCTITE 242 Works

LOCTITE 242 is applied to the threads before assembly. Once the adhesive becomes confined between the mating metal surfaces and oxygen is excluded, the anaerobic curing reaction begins. The adhesive solidifies within the thread interface, increasing resistance to loosening.

Its medium-strength formulation provides a balance between thread retention and serviceability. This makes it different from high-strength threadlockers intended for more permanent assemblies.

Suitable Materials

LOCTITE 242 is recommended for:

Steel

Stainless steel

Brass

Henkel identifies these metal substrates as recommended applications for LOCTITE 242. 

Technical Specifications

Property: LOCTITE 242

Product type: Threadlocker

Strength: Medium

Colour: Blue

Technology: Anaerobic acrylate

Chemical base: Methacrylate

Viscosity: 800–1,600 mPa·s (cP)

Fixture time: 5–20 minutes

Formulation: Thixotropic

Recommended substrates: Steel, stainless steel, brass

Maximum recommended thread size: Up to M36

Disassembly: Standard hand tools

Application: Threadlocking and sealing metal fasteners