All About Helicoils

The System

Thread inserts create high-strength fastenings in low-strength metal materials and have been well established in the market for over 50 years. These stainless steel thread inserts are formed into flexible spirals of proven quality wire with a rhombic profile. After installation, the tang can be broken off at the notch (predetermined breaking point) to allow through hole threads.

 

 

The Applications

Helicoil® inserts ensure high-strength threads transferring forces from flank to flank into the holding thread. This is a system of high reliability for which German and international industrial property rights have been filed and which is available worldwide. Helicoil® provides thread inserts produced
according to consistent material and quality specifications. This technology is the basis of national, aeronautical and military standards. Many leading large-scale users base their
manufacturing standards on this system.

Structural component

Wherever low-strength materials (e.g. aluminium, magnesium alloys and fibre-reinforced plastics) are used, Helicoil® is indispensable for thread reinforcement. This applies particularly to the aerospace industry, mechanical and plant engineering, the automotive industry and electrical and medical engineering. Thread reinforcement prevents wear of the threaded hole - even after frequent use. Helicoil® allows miniaturisation and lightweight construction in the development of serial parts. The required strength is provided by thread reinforcement with Helicoil®.

Rejects recovery and thread repair

Helicoil® thread inserts are internationally approved for the economical and permanent repair of damaged and worn out threads. Apart from repair of valuable individual components, the possibility to return and salvage large volume components which have been rejected due to faults in the thread production is of major importance.

 

The Advantages

Wear Resistance

Helicoil® thread inserts are made of austenitic chromenickel steel (minimum tensile strength of 1,400 N/mm²). The rolled thread has a high surface quality. This ensures a high-strength, wear-resistant thread with reduced friction torque. This also leads to an improved utilisation of the yield point of high-strength bolts. Torsion stress is considerably reduced compared to tapped threads.

 

 

 

 

 

 

 

Strength

The flexible characteristics of the HELICOIL® thread insert ensure even load and stress distribution and consequent optimum flank contact. Deficiencies in pitch and angle are balanced out over the entire length of the thread insert. With this, an optimum force transmission from bolt to threaded hole is achieved. The quality of screwed connection is considerably increased - for static as well as for dynamic operating loads.

 

 

The improved distribution of preload-force increases the fatigue strength of dynamically loaded bolts. This is why HELICOIL® inserts are also used for highstrength holding materials, e.g. steel or cast iron alloys.

 

 

 

 

 

 

 

Resistance to corrosion and thermal effects

The basic material of Helicoil® ensures that bolts do not seize under normal environmental influences. For thermally highly stressed bolted connections, Helicoil® thread inserts of nickel alloy based materials with and without coating are available. Elasticity and spring force are constant even unde high temperatures. If materials which are susceptible to corrosion, such as magnesium are used, Helicoil® utilises a special hard-coated version of high strength aluminium. Contact corrosion can therefore be ruled out.