Heli coils are made from stainless steel not soft metal. Once installed, the coil can't escape.
HeliCoil | HeliCoil Inserts | HeliCoil Screw Thread Inserts | HeliCoil Thread Repair Kits| HeliCoil Tools| Emhart Technologies USA| Armstrong UK | Bollhoff Germany | Recoil
Quote:
HeliCoil Screw Thread Inserts
HeliCoil Inserts are helically wound, precision formed coils of extremely hard stainless steel (18-8) diamond shaped wire. When installed into a HeliCoil tapped hole, the insert provides permanent conventional screw threads.
Materials & Platings
Materials:
Besides the standard 304 (18-8) stainless steel, HeliCoil inserts are also available in:
Inconel X-750
Nimonic 90
Phosphor Bronze
Nitronic 60
Titanium
|
I will give that heli coils are not optimal for frequently removed bolts and more for occasionally removed bolts ( Vs never removed bolts ) and require some care when inserting the bolt.
If the insert was installed too close to the surface, it will pull the top thread out during careless assembly. Ideally, the top of coil should be 1 turn below the surface assuming there isn't a deep chamfer.
If the new thread was not tapped deep enough, the bolt will bind and tend to unscrew the insert. All of these failure modes can be traced back to improper instillation.