Vibra-Tite 121 Blue Medium Strength Threadlocker for Optics & Firearms - 1.8 mL Tube Vibra-Tite 121 Blue Medium Strength Threadlocker is a removable thread-locking compound designed to help secure threaded fasteners against loosening caused by shock, recoil, and vibration. Its medium-strength formula makes it an excellent choice for firearm applications where screws need to remain secure during use but may still require future removal with standard hand tools. For firearm owners, builders, armorers, and gunsmiths, Vibra-Tite 121 is particularly well suited for optic mounting screws, red dot mounting plates, scope mounts, scope rings, accessory mounts, and other threaded firearm components. It can also be used on appropriately sized threaded muzzle devices and mounts when a removable, medium-strength threadlocker is desired and the application's temperature and manufacturer requirements are compatible. The compact 1.8 mL tube is ideal for the gun bench, range bag, or tool kit and provides enough product for multiple small-fastener applications without requiring a large bottle of threadlocker. Ideal for Optic Mounting & Optic Plates Recoil and repeated firing can place substantial vibration and shock on small threaded fasteners. Vibra-Tite 121 helps resist unwanted movement and loosening, making it a useful threadlocker for installing and maintaining firearm optics and mounting hardware. Common firearm applications include: Red dot optic mounting screws Pistol optic plates and adapter plates RMR-style optic mounting hardware Scope rings and scope mounts Picatinny and Weaver rail mounting screws Accessory mounts and threaded fasteners Muzzle devices and compatible muzzle-device mounts Set screws and other firearm hardware Always follow the firearm, optic, mount, or muzzle-device manufacturer's installation instructions, including recommended threadlocker type, torque specifications, and curing requirements. Not every muzzle or suppressor-mount application is appropriate for a medium-strength threadlocker. Medium Strength - Secure but Removable Unlike permanent high-strength threadlockers, Vibra-Tite Blue 121 is designed for applications that may eventually need to be disassembled. Once cured, fasteners can typically be removed using standard hand tools, making it especially useful for optics and firearm accessories that may later need to be serviced, adjusted, or replaced. Vibra-Tite 121 is formulated for threaded fasteners approximately 1/4" to 3/4" in diameter and provides good resistance to temperature and solvents. Fixture time is approximately 10-30 minutes, with a 24-hour full cure time. Vibra-Tite 121 Features Brand: Vibra-Tite Product: Blue Medium Strength Threadlocker Series: 121 Manufacturer Part Number: 12102 UPC: 745619121028 Container: 1.8 mL Tube Color: Blue Strength: Medium Form: Liquid Fixture Time: 10-30 Minutes Full Cure Time: 24 Hours Removal: Standard Hand Tools Fastener Size Range: 1/4"-3/4" Breakaway Torque: 100 lb-in Operating Temperature: -65AdegF to 300AdegF Standards: ASTM D-5363 (AN0321), MIL-S-46163A, NSF Non-Food Helps Prevent Fasteners from Loosening Under Recoil & Vibration Vibra-Tite 121 is an anaerobic threadlocker designed to lock and seal threaded fasteners and set screws. Once applied and properly cured, it helps prevent threaded components from working loose due to shock and vibration-making it a practical addition to any firearm maintenance or gunsmithing kit. Whether you're installing a red dot sight on a pistol, securing an optic mounting plate, mounting a scope, installing firearm accessories, or securing compatible threaded muzzle hardware, Vibra-Tite 121 Blue provides medium-strength retention while preserving the ability to remove the fastener later with hand tools. Shop Vibra-Tite 121 Blue Medium Strength Threadlocker for Optics & Firearms at BattleHawk Armory. Keep your optic mounts, mounting plates, firearm accessories, and compatible threaded components securely installed.