Loctite 243 — the medium-strength threadlocker that holds, and lets go.

Loctite 243 is a medium-strength anaerobic threadlocker by Henkel. It locks and seals threaded fasteners so they do not loosen from shock and vibration, and cures in the absence of air between close-fitting metal surfaces.

No. It is a one-component dimethacrylate ester. Shake the bottle thoroughly before use and apply directly to the threads.

It is a blue liquid that fluoresces positive under UV light. It is thixotropic, which means it does not migrate after application.

Medium strength. Compressive shear strength is 7.6 N/mm² (1,100 psi) per ISO 10123 on steel pins and collars. Breakaway torque on an M10 black oxide bolt is 26 N·m (230 lb·in).

Cure speed depends on the substrate, bond gap and temperature. Active metals like brass cure faster than passive metals like stainless steel. Higher temperature accelerates curing. For slow cures or large gaps, apply an activator such as 7471, 7649, 7088 or 7091.

Yes. It works on active metals (brass, copper) and passive substrates (stainless steel, plated surfaces). It also tolerates minor contamination from cutting, lubrication and anti-corrosion fluids. An activator speeds up the cure on passive metals.

Standard hand tools are normally enough. If the engagement length is excessive, apply localized heat of approximately 250°C to the nut or bolt and disassemble while hot.

It is not recommended in pure oxygen or oxygen-rich systems, should not be used as a sealant for chlorine or strong oxidizers, and is not normally recommended on plastics, particularly thermoplastics, where stress cracking could occur.

Store in the unopened container in a dry location at 8°C to 21°C. Storage below 8°C or above 28°C can adversely affect product properties. Do not return used product to the original container.