A threadlocker is a single component liquid or semi-solid adhesive. They cure at room temperature to a hard solid thermoset plastic when applied between steel, aluminium, brass and most other metal surfaces. They cure in the absence of air. The adhesive completely fills the gaps between mating threads to lock threads and joints. 

Benefits of Using LOCTITE^® Threadlockers

• Prevents unwanted movement, loosening and leaks
• Resist vibration loosening
• Single-component - clean and easy to apply
• Can be used on all sizes of metal fasteners - reduce inventory costs
• Seals threads - allow through-hole tapping

How to Choose a LOCTITE^® Threadlocker

When choosing a threadlocker, there are four things to consider:

1. Strength

• Low Strength (Purple): Ideal for fasteners <1⁄4" (6 mm). Easy disassembly using hand tools
• Medium Strength (Blue): Designed to be removable with standard hand tools on 1⁄4" to 3⁄4" fasteners
• High Strength: Designed to deliver high strength on 1⁄4" to 3⁄4" (6 mm to 22 mm) fasteners. For removal, it may require localised heat (>550°F/260°C), hand tools, and disassembly while hot

2. Viscosity

• Liquid Formulas: Everyday assembly; ideal for fine threads and blind holes
• Semisolid Formulas: Pocket-friendly, ideal for overhead applications

3. Application Methods

• Pre-Assembly: Most LOCTITE® liquid threadlockers are designed to be applied at the moment that parts will be assembled
• Post-Assembly: Wicking grade formula can be applied on parts that are already assembled

4. Materials Being Assembled

• All LOCTITE^® Threadlockers: Metal-to-metal applications

Learn More

Threadlocking User's Guide 

LOCTITE^® Success Stories