Red or Blue Threadlocker?
How to determine which color threadlocker to use

Although all Loctite products are in a red bottle, the threadlockers are often classified as red or blue. Why? This color-coding is to help you identify the different grades of threadlockers and choose the right one for your needs. See below for a quick reference on the strengths and applications of each color.

Red threadlocker is the highest strength. Once cured, it’s so strong that heat is required to disassemble attached parts. It should be used on applications where long lasting hold is required. Full cure time is 24 hours. Available in liquid or stick form.

Blue threadlocker is medium strength and is still pretty strong. However, this product allows separation of attached parts using hand tools. This makes it better for applications where parts may need to be disassembled for servicing. Full cure time is 24 hours. Available in liquid or stick form.

No matter which color, all threadlockers have a broad temperature resistance of -65°F to 300°F, some going up to as high as 650°F.