The thread insert has its origin in the aircraft industry where it was developed to overcome the problem of threads stripping in light alloy castings. Recoil cold rolled, helically wound thread inserts can be made from various grades of stainless steel, even phosphor bronze, to suit the required purpose.
Coatings such as cadmium or silver may be applied for corrosion protection.
The rhomboid cross section has a finish better than 32 microns, an extremely high tensile strength and a wide temperature tolerance.
Dry film lubricants are recommended for reduction of galling and binding.
The Helicoil (registered trade mark of Helicoil Inc, USA) performs the same function as the Recoil thread insert though it is constructed differently.
It is formed from a cylinder of metal which has then been threaded internally and externally.
The external thread and diameter of the Helicoil must be in close tolerance with the tapped hole. The Recoil insert must be larger than the tapped hole since it is compressed during installation before being allowed to spring back and anchor into position.
Recoil is the registered trade mark of Recoil pty Ltd, Australia.