helicoils

Helicoil is a brand-name term commonly used to refer to a type of threaded insert made from a coiled wire. These inserts are used to create or repair female threads in soft metals such as aluminum and magnesium, in harder alloys, and in some plastics. When installed correctly, a helicoil provides durable, replaceable threads that resist stripping and wear and can restore functionality to worn holes.

Construction and installation: A helicoil insert is a coil with internal threads that match a standard bolt size and a tang at one end to aid insertion. The host hole is drilled and tapped to the insert’s external size; the coil is then placed in the hole using a specialized installation tool. The coil is driven in, and the tang is broken off flush with the surface. The result is a hollow, threaded bore with good load distribution and resistance to pullout.

Applications and use: Helicoils are widely used for thread repair in engines, machinery, and structural hardware, and to provide new threads in aluminum, magnesium, and some plastics where the original material is too soft to hold a thread well. They are favored when thread strength, reusability, and repairability are important, or when a hole cannot be oversize re-tapped.

Materials and variants: They are produced in various materials, including stainless steel, alloy steel, nickel, and titanium, to suit different corrosion and strength requirements. Other brands and styles offer self-tapping inserts or different drive features, but the core principle remains the same: a helical coil that creates durable internal threads within an existing hole.