Loctite 242 Blue Threadlocker — 36 ml Medium-Strength Automotive Thread Lock for Metal Fasteners, Vibration Resistance

LOCTITE 242 Automotive Blue Threadlocker is a medium-strength, fast-setting adhesive designed to lock and seal threaded fasteners on metal components while still allowing future disassembly.

Engineered for professional garages and DIY mechanics, Loctite 242 is an OEM-tested threadlocker that bonds metal fasteners to resist vibration-induced loosening without permanently locking them. The 36 ml bottle supplies a versatile quantity for routine automotive maintenance and repair jobs, and its formulation works on a wide range of metals including stainless steel, aluminum, and plated surfaces.

How quickly does LOCTITE 242 set and reach full strength?

This threadlocker begins to set within about five minutes so parts stay in place while you work. It completes its cure to reach intended strength in roughly 24 hours under typical conditions, giving full holding performance the next day.

• Initial handling strength in ~5 minutes
• Full cure in approximately 24 hours at room temperature
• Cure speed depends on substrate, gap size, and temperature
• Best results on cleaned, dry metal surfaces

What types of fasteners and metals can I use it on?

LOCTITE 242 bonds well to a broad spectrum of metal fasteners, including passive metals that can be challenging for anaerobic adhesives. It is suitable for nuts, bolts, studs, and set screws across common automotive applications.

• Works on stainless steel, aluminum, plated, and common ferrous metals
• Ideal for valve cover bolts, oil pan bolts, and water pump bolts
• Useful on drive shaft bolts, carburetor studs, and rocker arm nuts
• Designed for threaded assemblies that require future serviceability

Can I disassemble fasteners treated with LOCTITE 242?

Yes—because it is a medium-strength threadlocker, treated fasteners can be removed with standard hand tools when service is required. It immobilizes hardware against vibration but does not create a permanent weld-like bond.

• Removable with typical wrenches or sockets
• Heavier seizing can be aided by heat if needed
• Apply sparingly to thread engagement area for easier removal
• Avoid over-application to prevent excess squeeze-out

How should I apply LOCTITE 242 for best results?

Preparation improves adhesion: clean threads of oil, dirt, and old sealant before application. Apply a small amount to the male threads, assemble, and let the product begin to set; the assembly can be handled after initial setting and fully cured in 24 hours.

• Degrease and dry threaded surfaces before use
• Apply to the bolt threads, not the nut, for controlled coverage
• Tighten to torque specification after application
• Store bottle capped in a cool, dry place to preserve shelf life

Who is this for? Technicians, professional mechanics, and knowledgeable DIYers who perform routine automotive repairs and maintenance will value LOCTITE 242 for its proven balance of reliability and serviceability. It suits anyone needing a medium-strength threadlocker that resists vibration and works across multiple metal types—especially for parts that will require removal later. Keep a 36 ml bottle in the shop for common tasks like securing engine covers, pumps, pans, and drivetrain components.