Blue Threadlocker Basics

Have you ever questioned which LOCTITE® Medium Strength Blue Threadlocker to use? Did you even know there are multiple kinds?

Of all our thread treatment applications, the Medium Strength Blue Threadlockers are the most commonly used. They are removable with standard hand tools on ¼ ” to ¾ ” fasteners, have fast fixture times, and are available in liquid, stick, paste, gel and tape form. The only question is, which blue threadlocker is right for your particular use?

The four types are:

  • LOCTITE® Threadlocker 242®
  • LOCTITE® Threadlocker 243™
  • LOCTITE® QuickTape® 249™ Blue Threadlocker Tape
  • LOCTITE® Blue Stick Threadlocker

Note: Although all LOCTITE® threadlocker bottles are red, the liquid in all four of the products below is blue. The red bottle is what distinguishes LOCTITE® threadlockers from other brands. Learn about the difference between Red, Blue, Green and Purple Threadlockers

LOCTITE® Threadlocker 242®

The typical repairs that utilize this type of medium strength threadlocker range from valve cover bolts to carburetor studs. This is known as our all-purpose threadlocker, and is also known as the “original threadlocker.” It eliminates the need for expensive lock nuts and lock washers, seals even when it vibrates, and protects threads from corrosion.

LOCTITE® Threadlocker 243™

LOCTITE® 243™ threadlocker is an upgraded version of LOCTITE 242®, and is more of a general-purpose member of our “blue crew.” It is designed to have improved oil tolerance with surface-insensitive properties (plated fasteners no longer require primer), combined with the same overall benefits of the original Blue Threadlocker 242®. Projects that would need this type of application include rocker studs, oil pans, disc brake calipers, pulley assemblies and many more.

LOCTITE® 242® and 243™ liquid blue threadlockers were so successful that we created two alternative physical forms of the product, for easier use on a wide variety of applications, described below:

LOCTITE® Stick Threadlocker

LOCTITE® Sticks are created in a semi-solid form, for easy overhead applications. They are small enough to be “pocket friendly,” and will not leak, drip, or spill. They are also available for primerless and oil-tolerant applications.

LOCTITE® QuickTape® 249™ Threadlocker

LOCTITE® QuickTape® is supplied in a low-tack film to provide a convenient and easy-to-use package, especially where a liquid product may be too fluid to stay on a part or may be difficult to apply. This product can be used on the assembly either immediately or days later, and provides consistent strength on a variety of metal substrates.

Both the stick and tape threadlocker products are used for difficult repairs and overhead applications, and both can be used for cleaner application purposes. They are most commonly used on applications that involve valve cover bolts, rocker arm adjustment nuts, carburetor studs, etc.

Now that you know the basics and the differences among our “blue crew” of threadlockers, it’s easy to see the benefits that each one can bring to help you complete every project with precision and quality.

You might also be interested in: When and Why to Use Purple Threadlocker