The standard HeliCoil helically wound insert with precision-formed rounded coils and a diamond shaped cross-section. When installed, they provide the hole with smooth free running threads.

HeliCoil Screw Lock Inserts have all the characteristics of free running inserts but in addition, one or more coils in the middle of the screw lock insert are polygon shaped. These coils serve as a locking device by gripping the threads of the installed screw, effectively preventing the screw from loosening under vibration or impact.

HeliCoil Screw Lock Inserts permit frequent removal and reassembly of bolts without appreciable loss of torque. They positively secure the screw against loosening caused by vibration and shock and they will not relax their grip on the screw even in tough metals such as cast iron, alloy steel, titanium etc.

HeliCoil TwinSerts restore damaged holes to the original thread size. They are used for salvaging incorrectly tapped holes and holes that are stripped, off-centre, or damaged.

HeliCoil TwinSerts should be used when the oversize condition of the hole is beyond the corrective range of HeliCoil OverSize Inserts.

As the name implies, a HeliCoil TwinSert consists of two HeliCoil inserts - an Outer Insert, and an Inner Insert. The Outer Insert is always free running while the Inner Insert can be either free running or screw-locking.

HeliCoil TwinSerts are available in numerous nominal thread sizes.