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LOCTITE® 243 Blue Medium Strength Threadlocker

Known as LOCTITE 243 Blue Threadlocker

Features and Benefits

Locks and seals metal nuts and bolts to prevent loosening due to shock and vibration. Medium strength, removable with hand tools.
LOCTITE® 243 is a blue, general purpose threadlocker that provides a medium strength bond. It works on all metals, including passive substrates such as stainless steel, aluminum and plated surfaces without the use of primer. Proven to be tolerant of minor contamination due to industrial oils, e.g., motor oils, corrosion prevention oils and cutting fluids.
  • Prevents fastener loosening on vibrating assemblies, e.g. pumps, gear boxes or presses
  • Works on all metals, including passive substrates (e.g. stainless steel, aluminum, plated surfaces)
  • Proven to tolerate minor contamination by industrial oils, e.g. motor oils, corrosion prevention oils and cutting fluids
  • Permits disassembly with hand tools for servicing
  • NSF/ANSI 61 Certified
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Documents and Downloads

Safety Data Sheets and RoHs
LOCTITE® 243, 250 ml Bottle 1329505 en-US
IDH: 1329505
EAN: 079340438989

Size Case: 250 ml Bottle

Quantity: 10.0/case

LOCTITE® 243, 0.5 ml Bottle 1330255 en-US
IDH: 1330255
EAN: 079340439009

Size Case: 0.5 ml Bottle

Quantity: 100.0/case

LOCTITE® 243, 1 l Bottle 1330333 en-US
IDH: 1330333
EAN: 079340439016

Size Case: 1 l Bottle

Quantity: 4.0/case

No documents found

Technical Information

Application method Dispense Gun, Dispense System, Manual
Application temperature -55.0 - 180.0 °C (-65.0 - 360.0 °F )
Applications Threadlocking
Breakaway torque, M10 Steel Nuts/Bolts ~26.0 N·m (230.0 in./lb. )
Color Blue
Cure type Anaerobic Cure
Fixture time 10.0 min.
Key characteristics Disassembly: Removable, Fluorescent, General Purpose, Oil Tolerant, Primerless, Strength: Medium Strength, Thixotropic
Physical form Liquid
Prevail torque, M10 Steel Nuts/Bolts 5.0 N·m (40.0 in./lb. )
Recommended for use with Metal, Metal: Passive Metal
Specific gravity, @ 23.0 °C 1.08
Viscosity, Speed 20 RPM 2150.0 mPa·s (cP)

How to

LOCTITE 243 Threadlocker Product Overview

Step by Step Guide

1. Preparation - Cleaning

It is recommended to use LOCTITE® SF 7070™ to degrease and clean surfaces prior to applying threadlocker adhesive.

2. Preparation - Activation

If cure speed is too slow due to passive metals (stainless steel, aluminum and plated metals) or low temperature (below 5°C), use activator LOCTITE® SF 7649™ (see cure speed vs activator graph in the TDS).

3. Application

Apply liquid threadlocker to the engagement area. For manual dispensing, the use of a peristaltic handgun or the LOCTITE® Pro Pump is recommended to ensure a consistent application volume.

4. Application - Through Hole

Insert bolt and apply threadlocker to the exposed thread. Assemble nut and tighten to the correct/specified torque.

5. Application - Blind Hole

Apply several drops of liquid threadlocker down the sides of the blind hole filling the lower third. Apply several drops to the bolt.

6. Assembly

Assemble and tighten. If several bolts are being assembled, torque them down to the correct value within the fixture.

7. Disassembly - Hand Tools

Disassemble with standard hand tools.


For the disassembly of corroded or seized parts use LOCTITE® LB 8040™ Freeze and Release.

Where to Buy

Buy Online

Locks and seals metal nuts and bolts to prevent loosening due to shock and vibration. Medium strength, removable with hand tools.

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    Frequently Asked Questions

    Learn with LOCTITE®XPLORE

    How to Secure Threaded Assemblies

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