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LOCTITE 2620 High-Temperature Threadlocker for Extreme Service Conditions

LOCTITE 2620 High-Temperature Threadlocker is a red, one-component anaerobic threadlocking paste engineered for threaded fasteners exposed to severe vibration, shock, and extreme operating temperatures. The product cures when confined between close-fitting metal threads in the absence of air, forming a durable bond that helps prevent fasteners from loosening and threaded joints from leaking. Its high-strength formulation is especially suitable for demanding industrial equipment where conventional threadlockers may not provide sufficient thermal stability.

This high-viscosity, thixotropic paste stays where it is applied instead of running across the component. Its controlled consistency supports precise dispensing onto horizontal, vertical, and overhead threaded assemblies. LOCTITE 2620 requires no mixing and is commercially available in a syringe format, simplifying application during manufacturing, equipment assembly, preventive maintenance, and field repair.

Key Benefits of LOCTITE 2620 High-Temperature Threadlocker

LOCTITE 2620 High-Temperature Threadlocker is specially formulated for applications requiring temperature resistance up to 343°C. Its resistance to severe heat makes it appropriate for threaded connections located near engines, exhaust equipment, industrial heaters, furnaces, thermal-processing machinery, and other high-temperature systems. The cured material maintains useful locking performance during elevated-temperature exposure, although every critical assembly should be validated under its actual operating cycle.

The uncured product has a typical specific gravity of 1.16 and a viscosity range of approximately 20,000 to 70,000 mPa·s at 25°C under the stated test method. This paste-like consistency helps fill the spaces between engaged threads and reduces migration during assembly. After 24 hours at 25°C, Henkel reports a breakloose torque range of approximately 11.4 to 34 N·m on degreased 3/8 × 16 steel nuts and bolts pretorqued to 5 N·m.

Applications for LOCTITE 2620 High-Temperature Threadlocker

LOCTITE 2620 High-Temperature Threadlocker is suitable for locking and sealing metal nuts, bolts, studs, plugs, and threaded fittings subjected to intense heat, vibration, impact, and mechanical loading. Typical application areas may include industrial motors, power-generation equipment, heavy machinery, compressors, pumps, high-temperature processing systems, exhaust-related assemblies, and demanding maintenance operations. Henkel specifically associates the product with industrial manufacturing and electric-motor applications.

Published testing also demonstrates resistance after exposure to motor oil, automatic-transmission fluid, unleaded gasoline, brake fluid, water-glycol mixtures, and isopropanol under defined laboratory conditions. Actual chemical resistance depends on temperature, fluid concentration, exposure duration, thread geometry, and curing conditions, so testing on representative assemblies remains essential.

How to Apply LOCTITE 2620 High-Temperature Threadlocker

Before application, clean the internal and external threads with a compatible LOCTITE cleaning solvent and allow them to dry. On inactive metals, plated surfaces, large gaps, or assemblies where curing is too slow, LOCTITE SF 7649 or SF 7471 activator may be applied before the threadlocker. Avoid touching the dispensing tip directly against metal because this may contaminate or clog the nozzle.

For through holes, apply several drops to the bolt around the nut-engagement area. For blind holes, dispense the material into the lower internal threads so trapped air does not force uncured adhesive outward during assembly. When sealing threaded fittings, apply a continuous 360-degree bead around the leading male threads while leaving the first thread free, then assemble and tighten the connection as required.

Storage and Removal of LOCTITE 2620 High-Temperature Threadlocker

Store unopened LOCTITE 2620 High-Temperature Threadlocker in a dry location, preferably between 8°C and 21°C. Temperatures below 8°C or above 28°C may adversely affect product properties. Standard hand tools may remove many cured assemblies; for large diameters or long engagement lengths, localized heating to approximately 250°C may be required before disassembly.

For manufacturers and maintenance professionals requiring dependable fastener security in severe environments, LOCTITE 2620 High-Temperature Threadlocker provides high strength, non-running application, chemical resistance, and exceptional high-temperature capability. Explore our industrial threadlockers for motors, machinery, pumps, compressors, high-temperature equipment, and vibration-resistant fastening applications.

industrial threadlockers