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LOCTITE® 243 Blue Medium Strength Threadlocker
Features and Benefits
This iconic threadlocker 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 without primer, including passive substrates such as stainless steel, aluminum, and plated surfaces. Suitable for use on most oil-coated, 'as-received' fasteners without cleaning.
- Prevents 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 ordinary hand tools for easy service and maintenance
- P1 NSF Reg. No.: 123000
Documents and Downloads
Looking for a TDS or SDS in another language?
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
Step by Step Guide
1. Preparation - Cleaning
It is recommended to use LOCTITE® SF 7063, SF 7064, or 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 7240 or 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.
Frequently Asked Questions
What products can I use to prevent vibration loosening of parts? / How do I prevent vibration loosening and leak paths?
What temperatures can threadlockers/thread sealants/gasketing materials work up to?
Are threadlockers/sealants/gasketing materials resistant to fluids such as gasoline, diesel, engine oil, water, glycol, acids, alkalis, hydraulic fluid, etc.?
Can threadlockers be used as thread sealants? / Can thread sealants be used as threadlockers?
LOCTITE® 243
This iconic threadlocker locks and seals metal nuts and bolts to prevent loosening due to shock and vibration. Medium strength: removable with hand tools.