Loctite 243 Medium Strength Threadlocker 10ml

Loctite 243 is a one-component, blue, medium strength anaerobic threadlocker. It locks and seals threaded fasteners that need normal disassembly with standard hand tools.

It cures between close-fitting metal surfaces, works on passive substrates such as stainless steel and plated surfaces, and tolerates minor oil contamination.

Where this product is used

• Locking nuts, bolts and studs that need normal disassembly
• Fasteners on passive surfaces such as stainless steel and plated parts
• Threads with minor oil contamination
• Small and large fasteners from M6 to M16 (breakaway data in the specification)

Features

• Medium strength, removable with standard hand tools
• Thixotropic liquid that stays where it is applied
• One component, no mixing
• Blue liquid with positive fluorescence under UV light, useful for inspection
• Tolerates minor oil contamination
• Anaerobic cure, with an activator as secondary cure
• Cold strength tested to -75 °C

Key specifications

Available sizes

Selecting the right option

For a low strength grade on small fasteners see Loctite 222 Low Strength Threadlocker; for high strength see Loctite 263 High Strength Threadlocker. For another medium strength grade see Loctite 242 Threadlocker Anaerobic Adhesive Blue 50ml.

Using it

Shake the product thoroughly before use.

Cure speed depends on the materials, the gap and the temperature; the cure-speed graphs are in the Henkel data sheet.

Where hand tools will not release the fastener, apply localised heat to about 250 °C and disassemble while hot.

Storage and handling

Store unopened in a dry location. Optimal storage is between 8 °C and 21 °C. Storage below 8 °C or above 28 °C can adversely affect the properties of the product.

Limits and safety

Not recommended for pure oxygen or oxygen-rich systems, or as a sealant for chlorine or other strong oxidising materials. Plastics can stress crack. The Henkel data sheet states no operating temperature range; cold strength was tested to -75 °C. The current data sheet lists no approvals.

Frequently asked questions

What is the breakaway torque of Loctite 243?

On M10 black oxide bolts and mild steel nuts, cured 24 hours at 23 °C, Henkel gives 22 N·m breakaway and 9 N·m prevail torque (ISO 10964, unseated).

Can Loctite 243 be removed with hand tools?

Yes. Henkel says to remove it with standard hand tools. Where they do not work, apply localised heat to approximately 250 °C.

What is the viscosity of Loctite 243?

1,300 to 3,000 mPa·s (Brookfield RVT, spindle 3, 20 rpm, 25 °C). It is thixotropic.

Can Loctite 243 be used on oily threads?

Henkel states it tolerates minor oil contamination, and works on passive substrates such as stainless steel and plated surfaces.

Does Loctite 243 have any approvals?

The current Henkel data sheet lists no approvals; contact AIMS if you need a certificate for a specific application.

How fast does Loctite 243 cure?

Cure speed depends on the materials, the gap and the temperature. The cure-speed graphs, at 23 °C, are in the Henkel data sheet.

Related products

See also: Loctite 222 Low Strength Threadlocker, Loctite 263 High Strength Threadlocker, Loctite 242 Threadlocker Anaerobic Adhesive Blue 50ml, Loctite 290 Medium to High Strength Threadlocker, Loctite 248 Medium Strength Threadlocker Stick 19g.