MS21209C0815LSF - Screw Threaded Insert by Helicoil Stanley Engineered Fastening

The Heli-Coil MS21209C0815LSF is a military-standard screw-locking wire thread insert designed to generate high-strength, wear-resistant internal threads in precision components. Formed from cold-drawn 304 stainless steel wire with a precision diamond-shaped cross-section, this tanged insert features a specialized series of straight chordal segments along its middle coils. These flat chords flex outward as a male bolt is threaded into the assembly, creating a controlled, continuous prevailing torque that grips the bolt securely. This configuration ensures exceptional vibration resistance, completely preventing rotational hardware loosening under harsh operational shocks without requiring secondary safety wires or lock washers.

Internal Screw-Locking Mechanism Resilient chordal segment coils apply continuous prevailing locking torque to securely clamp mating fasteners against intense vibration.

Standard Driving Tang Formed with a robust drive tang on the leading coil to ensure reliable installation tool engagement and exact depth control.

High-Tensile CRES Construction Crafted from work-hardened corrosion-resistant steel to shield soft parent materials from internal thread stripping, galling, and thread wear.

Dry Film Lubricant Finishing Pre-coated with a dry film lubrication layer that stabilizes installation torque values, optimizes seating force, and eliminates friction wear during assembly.