Product Overview

Loctite Blue 242 Threadlocker is a medium-strength, removable adhesive designed to lock and seal threaded fasteners that need to stay put under vibration—but may require later removal for service or adjustments. It’s ideal for metal fasteners between 1/4 in. and 3/4 in., making it a favorite among mechanics, contractors, and equipment assemblers.

The 242 formula prevents loosening due to shock, vibration, or temperature fluctuations, while also sealing out moisture and corrosion. It cures anaerobically (in the absence of air) once applied to the threads and the fasteners are assembled.

Unlike permanent threadlockers (like red formulas), Loctite 242 allows future disassembly using standard hand tools—making it perfect for machines, vehicles, tools, and home improvement projects where reliability and serviceability are both required.

Technical Specs

• Brand: Loctite
• Product Name: Threadlocker Blue 242
• Strength: Medium
• Removability: Removable with hand tools
• Thread Size Range: 1/4 in. to 3/4 in.
• Cure Type: Anaerobic (sets in absence of air)
• Typical Use Cases: Fasteners in motors, pumps, gearboxes, tools, and appliances
• Color: Blue
• Resistance: Vibration, moisture, corrosion, mild chemicals
• Temperature Range: -65°F to 300°F (-54°C to 149°C)

What It’s Good For

Best for medium-duty fastening where parts need to hold tight under use, but may need to be serviced later. Popular for motorcycles, lawn mowers, industrial equipment, and shop-built assemblies.

Compared to Other Threadlockers

• Blue 242 = medium strength, removable
• Red 271 = high strength, permanent
• Purple 222 = low strength, small fasteners
  Loctite Blue 242 hits the balance between secure hold and serviceability.

Also Known As

• Loctite Threadlocker 242
• Blue Medium Strength Threadlocker
• Removable Thread Adhesive
• Loctite Blue Bolt Sealer