threadlockers

Threadlockers are anaerobic adhesives designed to lock threaded fasteners and seal against leaks by curing in the absence of air between close-fitting metal surfaces. When applied to a bolt or screw and assembled into a tapped hole, the confined adhesive cures to a solid polymer that resists vibration, preventing loosening and galling while providing some corrosion protection.

They are commonly categorized by removal force and purpose. Strength levels range from low or light (easily removable) to medium (standard service) and high (difficult to remove). Some products are marketed as permanent or bearing-retaining variants. Colors used by manufacturers help indicate strength, but there is no universal standard, so it is important to consult the specific product data for the correct choice.

Applications include fasteners in automotive, machinery, plumbing, electronics, and consumer products where vibration could loosen joints. Threadlockers reduce fretting, protect against moisture ingress, and simplify field maintenance. They are typically suitable for metal-to-metal threads; compatibility with plastics or coatings should be verified, and proper surface preparation is essential.

Usage guidelines: clean and dry the threads, then apply a uniform amount to one mating thread or to the internal threads if applicable. Assemble and torque to specification; the material cures in place to provide holding strength. Initial handling strength develops quickly, with full cure over time at ambient temperature. Removal usually requires heat, mechanical disruption, or specialized solvents, depending on the product’s strength.

Limitations include potential incompatibility with porous substrates, certain coatings, or lubricants, and the possibility of over-application causing excessive stiffness or seizure. Threadlockers are not substitutes for proper fastener selection, torque, or locking hardware in high-load or critical applications.