What’s the difference between red and blue Loctite threadlocker?
Loctite threadlockers are primarily designed to prevent fasteners from leaking or loosening from vibration. The difference between red and blue threadlocker is a matter of strength and removability. Loctite threadlocker blue is designed to easily be replaceable with common tools, whereas red is a more permanent fix. If you have trouble keeping it straight, here’s a helpful rhyme to jog your memory: “Blue, easy to make new. Red, full strength ahead!”
For a hold that can be easily removed, Loctite Threadlocker Blue 242 is the hero. It’s perfect for motorized and nonmotorized parts that need occasional servicing, like car parts (oil pans, water pumps, etc), or even motorized yard equipment, bicycles, furniture and much more.
For parts that need a more permanent hold, like structural bolts in a home, auto suspensions and frames, or any other heavy machinery, Loctite Threadlocker Red 271 is the answer. This industrial grade threadlocker packs a stronger punch than the blue and can only be removed by heating the parts to 500F.