Permatex High-Strength Threadlocker Red is ideal for heavy-duty applications 3/8? to 1? (10mm to 25mm) Red threadlocker is well-suited for permanently locking studs and press fits. Threadlocker RED adds 3,000 PSI holding power on slip and press fit assemblies, and replaces set screws and snap rings. Permatex’s Threadlocker Red locks against vibration loosening. May require heat or special tools for removal.