HeliCoil Heli-Coil Locking Insert, Stainless Steel, Tanged, Course Thread, M8 x 1.25 Thread, 16mm Overall Length

Heli-Coil inserts are larger in diameter before installation than the tapped hole. During installation the inserting tool applies torque to the tang reducing the diameter of the leading coil permitting it to enter the tapped thread. After installation, each high tensile coil of the insert expands outward with a spring-like action permanently anchoring the insert.