Loctite 263 High-Strength Threadlocker 50ml — Red, Permanent Locking for Heavy-Duty Fasteners

Loctite 263 is a high-strength, red threadlocking adhesive in a 50ml bottle designed to permanently lock and seal threaded metal and plastic fasteners under demanding conditions.

This dual-cure acrylic dimethacrylate ester threadlocker is formulated for heavy-duty assemblies where vibration, torque and solvent exposure threaten fastener integrity. It works by filling the gaps between mating threads and curing to a tough polymer that resists loosening and leakage. The fluorescent red color helps you see where the product is applied, and the dual-cure chemistry ensures reliable setting even in close-fitting or plated components.

How does Loctite 263 secure fasteners in heavy-duty equipment?

Loctite 263 forms a permanent, rigid polymer between threads that resists vibration and high shear loads. Because it is a dual-cure acrylic formulation, it can cure anaerobically in the absence of air and acceleratively on metal surfaces for a reliable bond in service environments.

• Creates a high-strength lock that prevents back-out and loosening under torque.
• Fills gaps and seals threads to reduce fretting and corrosion.
• Performs on various metals and some plastics used in industrial assemblies.
• Fluorescent red hue allows quick visual confirmation of application.

How fast does the adhesive cure and when can parts be used?

Cure speed depends on gap size, substrate and temperature; full fixture strength typically develops within 24 hours at room temperature. Initial handling strength can be achieved sooner on close-fitting steel threads or with elevated temperatures, but allow full cure for maximum shear performance.

• Typical full cure: approximately 24 hours at 20–25°C on standard steel threads.
• Faster curing on active metal surfaces; slower in larger gaps or inert substrates.
• Elevated temperatures accelerate cure; colder conditions slow it down.

What surfaces and applications are suitable for Loctite 263?

This threadlocker is intended for metal fasteners and many engineering plastics in applications requiring permanent locking. It is particularly suited to studs, heavy bolts and assemblies in motors, gearboxes and other machinery where high strength and long-term stability are necessary.

• Ideal for studs into motor housings, heavy machinery bolts and critical joints.
• Works on steel, stainless steel, plated parts and some plastics—test plastics first.
• Not recommended where future disassembly is required without heat or mechanical removal.

How should I apply Loctite 263 for best results?

Prepare mating surfaces by removing grease, oil and debris; apply a few drops to the threads and assemble immediately. Wipe off excess and allow the adhesive to cure undisturbed to reach its specified strength.

• Clean threads with solvent or a degreaser before application.
• Use a small amount directly on threads—avoid over-application to reduce mess.
• Assemble parts promptly; clamp or fixture if necessary until cured.
• Store the 50ml bottle upright in a cool, dry place to preserve shelf life.

Who is this product for?

Loctite 263 is aimed at professional mechanics, maintenance technicians and industrial assemblers who need a dependable permanent threadlocker for heavy-duty fasteners. Choose this product when maximum locking strength and long-term resistance to vibration and solvent attack are priorities, and when visual confirmation of application is helpful. It is not ideal for assemblies that require routine disassembly without heat or destructive methods.