MS21209F0815L by HELI-COIL

The Heli-Coil MS21209F0815L (Heli-Coil Part Number: 3591-2CNW246) is a military-standard screw-locking wire thread insert engineered to establish high-strength, permanent internal threads in lightweight metals, alloys, and composite host materials. Precision-coiled from cold-drawn 304 stainless steel wire with a specialized diamond-shaped profile, this tanged insert features internal locking coils with straight, chordal segments. When mating male hardware is introduced, these flat segments flex outward, exerting a consistent prevailing torque that grips the fastener securely. This delivers exceptional vibration resistance, preventing dangerous rotational loosening under harsh dynamic loads while protecting soft parent materials from internal thread stripping, galling, and wear. Pre-coated with a specialized dry film lubricant, it reduces friction during assembly and ensures uniform torque-tension dynamics.

Internal Screw-Locking Profile Deformed chordal coils apply continuous prevailing locking torque to secure mating hardware tightly against severe operational shock and vibration.

Standard Driving Tang Engineered with an integrated drive tang on the leading coil for positive tool engagement and rapid, controlled depth placement.

Austenitic Stainless Steel Construction Crafted from work-hardened corrosion-resistant steel to create a wear-proof thread foundation that shields soft alloys from thread fatigue and stripping.

Dry Film Lubricant Coating Pre-treated with a specialized dry film lubricant finish to stabilize installation torque values, optimize clamping force, and eliminate friction-induced galling.