Perma-Thread Inserts are precision formed coils of extremely hard stainless steel (18-8) diamond shaped wire. When installed into a Perma-Thread tapped hole, the insert provides permanent conventional screw-threads.
The insert has a driving "tang" for installation which is notched for easy removal.
Perma-Thread Inserts are larger in diameter before installation than the tapped hole. During installation the inserting tool tightens the insert which reduces the diameter of the leading coil so it can enter the tapped hole. After installation, each high tensile stainless steel coil expands outward against the tapped hole to permanently anchor the insert.