HeliCoil® is ideal for designing in to components. Strength and reusability of threads is guaranteed in lightweight and malleable materials such as aluminium and magnesium. The fasteners can be fitted using automation and in this context Plus or TangFree inserts to improve productivity.
Originally deployed as a retrospective product used to repair damaged threads, these applications continue to apply to the HeliCoil® range.
The original HeliCoil® wire thread insert is a fully formed insert that is significantly larger in diameter in its free state than the hole that it is intended for. It has to be pre-wound using an installation tool prior to fitting the connector screw or bolt and then when it is in position and the tool removed it expands, like a spring, to fit precisely into the tapped hole providing a hardwearing screw thread with the greatest tensile strength - greater than the original tapped hole.
Benefits include good corrosion and heat-resistance, wear-free in operation, reject recovery, uniform load and stress distribution, easy identification even when installed (by using colouring or surface treatment). The HeliCoil® is available in different variants for very different requirements and the components are available in both metric and imperial dimensions.
There are two basic types of HeliCoil®:
Free running
Every thread of the insert with its precision formed, rhombic profile is free running. The result is an internal thread true to gauge that can be used on both sides. The natural steel colour allows easier identification when the HeliCoil® free running is installed.
A seal of quality, a rhombic imprint at the end of the last thread, unmistakably identifies each Böllhoff HeliCoil® free running as an original Böllhoff product.
Screwlock
The HeliCoil® screwlock provides the same benefits regarding threads as the HeliCoil® free running, but in addition, an integrated screw-locking area serves as a screw lock.
Locking of the screw is achieved by one or several polygonal-shaped threads that clamp the flanks of the fully tightened screw. The result is an elastically resilient frictional locking.
The HeliCoil® screwlock can be recognised thanks to its red colour. The HeliCoil® screwlock inserts can only be used with screws of property class 8.8 or higher.
Three applications serve to demonstrate the versatility of HeliCoil®. The first is a component that forms part of a control console used in a printing press, which has a high operating temperature range, and in which there are repeated fastening and unfastening cycles due to maintenance and repair schedules. The material of the component is G-AISi9 Mg alloy into which 12 HeliCoil® are inserted.
In a second application HeliCoil® is used in a pressure die cast aluminium carrier plate for electronic components. Similar applications can be found in hand tools, lamps, electrical appliances and many more.
In the automotive sector HeliCoil® is found in die cast aluminium gear box casings, where 14 x M14 x 1.5mm HeliCoil® components are deployed. HeliCoil® is also used in exhaust systems, engines and even satellites.
