MS21209F115L - Screw Threaded Insert by Helicoil Stanley Engineered Fastening

The Heli-Coil MS21209F115L is a high-performance, military-standard screw-locking wire thread insert engineered to form high-strength, permanent internal threads in precision engineering setups. Formed from cold-drawn 304 stainless steel wire with a specialized diamond cross-section, this tanged insert features a unique series of straight chordal segments on its internal coils. These flat chords expand elastically when a male bolt is introduced, establishing a precise, continuous prevailing torque that prevents rotational hardware loosening. It provides superior vibration resistanceagainst harsh cyclic stress without requiring loose structural locking wires or secondary washers, protecting threads in low-strength parent metals from wear, erosion, and failure.

Internal Screw-Locking Resilient chordal segment coils exert continuous structural clamping torque to lock mating male bolts safely against severe vibrational forces.

Tanged Production Anchor Built with a robust driving tang on the leading installation coil to ensure positive engagement with manual or automatic tooling.

High-Tensile CRES ProtectionManufactured from work-hardened corrosion-resistant steel to provide a wear-proof thread foundation that shields soft alloys from stripping.

Dry Film Lubricant Finishing Pre-coated with a dry film lubrication layer to stabilize installation torque values, optimize seating force, and eliminate friction galling.