Henkel LOCTITE GRD AV High Strength Threadlocker for Large Coarse Threads

LOCTITE GRD AV High Strength Threadlocker Performance

The adhesive cures when it is confined between close-fitting metal surfaces and air is excluded. This anaerobic cure mechanism fills microscopic spaces between engaged threads and forms a tough polymer layer that locks the fastener and helps seal the threaded path. The uncured material has a typical specific gravity of 1.07 and a viscosity range of approximately 100 to 250 mPa·s, allowing it to flow across coarse threads while remaining controlled during dispensing.

After curing, the material provides high-strength fastening performance and resistance to common industrial fluids. Henkel reports retained strength after exposure to motor oil, phosphate ester, water, ethylene glycol, ethanol, and acetone under specified laboratory conditions. The product is also tested to applicable regional requirements of MIL-S-22473E, while North American production lots are tested against relevant ASTM D5363 requirements.

Applications for Large Coarse Threaded Assemblies

LOCTITE GRD AV High Strength Threadlocker is suitable for large nuts, bolts, studs, pipe plugs, threaded fittings, machinery fasteners, power equipment, pumps, compressors, gear systems, industrial vehicles, and heavy mechanical assemblies. It is particularly useful when a permanent or difficult-to-remove connection is preferred and conventional mechanical locking methods may add parts, weight, installation time, or inventory complexity.

The liquid can be applied to through holes, blind holes, and sealing applications. For through-hole assemblies, several drops are placed on the bolt around the nut engagement area. For blind holes, the adhesive is applied to the internal threads near the bottom. For sealing work, a continuous 360-degree bead is applied to the leading male threads while leaving the first thread free.

7 Benefits of LOCTITE GRD AV High Strength Threadlocker

• High locking strength: Helps prevent vibration-related loosening in demanding assemblies.
• Thread sealing: Fills thread voids and reduces potential leakage paths.
• One-component use: Requires no weighing, measuring, or resin mixing.
• Medium viscosity: Provides controlled coverage on large and coarse threads.
• UV fluorescence: Supports quality-control inspection after application.
• Fluid resistance: Maintains useful strength after exposure to several industrial liquids.
• Production flexibility: Suitable for manual dispensing and controlled assembly processes.

Surface Preparation, Application, and Disassembly

Clean internal and external threads with a suitable LOCTITE cleaner and allow them to dry. Shake the bottle before use and avoid touching the dispensing tip directly to metal, which can promote curing inside the nozzle. Inactive metals or slow-curing conditions may require LOCTITE SF 7471 Activator or LOCTITE SF 7649 Activator. Apply enough product to fill the engaged threads, assemble the parts, and tighten them to the specified torque.

Because this is a high-strength threadlocker, routine removal with ordinary hand tools may be difficult. Henkel recommends localized heating of the nut or bolt to approximately 250°C, followed by disassembly while hot. Cured residue can be removed through a combination of compatible solvent soaking and mechanical abrasion. Always review the current safety data sheet and protect nearby heat-sensitive components during removal.

Official Resources and Related Threadlocking Products

Review the official Henkel LOCTITE GRADE AV product page and the official LOCTITE GRD AV technical data sheet for current performance data, application guidance, package options, and safety documentation.

Explore our high-strength threadlockers for additional permanent fastening solutions, or browse our industrial threadlockers for low-, medium-, and high-strength grades. Store unopened containers in a dry location, ideally between 8°C and 21°C. Contact our sales team for 50 ml or 250 ml availability, quotations, export documentation, compatible activators, and application support.