The latest generation for this technology is called GRIPCOIL.

Rm = Tensile strength minimum 1400 N/mm2
HV = Vickers hardness minimum 425 HV 0,2
RZ = Roughness depth approximately 2,5 μm
μG = Reduced and constant thread friction, results in a heightened pre-stressing force FV
τt = Reduction in the torsion stress in the screw shank

Wear and Tear Stability

GRIPCOIL thread inserts are manufactured from austenitic chrome-nickel-steel (tensile strength of a minimum 1400 N/mm2). The formed thread provides a high surface quality. This guarantees a heavy-duty, wear and tear resistant thread with an extremely low constant thread friction force. This allows for a constant pre-stressing being achieved with the identical tightening torque upon repeated re-screwing. This leads simultaneously to a better utilisation of the yield point for high strength screws. The torsion stress is noticeably reduced hereby: In comparison with cut threads, the surface roughness depth is up to 90% lower with GRIPCOIL© plus.

Stronger Assemblies

The flexible characteristics of the GRIPCOIL thread inserts provide an uniform loading and tension distribution and with that, a perfect thread pitch angle. Pitch and angle defects are balanced out over the entire length of the thread insert. Therefore an ideal force transfer is achieved between the bolt and the nut thread. The durability of the thread connection is significantly increased. This applies to both static and dynamic work loads.

Due to the better repartition of the screw-load, the fatigue strength of a screw will be encreased. This is an argument for to use GRIPCOIL® even in high strength parent material, for example steel or casted iron.

Corrosion Resistance, wide Temperature Range

The material properties of the GRIPCOIL ensure that locking and tight gripping of screws under normal environmental conditions does not occur. GRIPCOIL thread inserts made from nickel based materials (INCONEL and NIMONIC 90) are available for thermal high stressed thread connections, with or without any coating. Elasticity and springiness is preserved even under high temperatures.

GRIPCOIL from high-strength hard coated aluminium has been specially developed for utilisation with materials liable to high corrosion such as magnesium. Contact corrosion is hereby ruled out.

Freedom of design

GRIPCOIL thread inserts allow a wide range for the designer in the choice of materials and material thickness. The actual trend towards lightweight design (for example from magnesium) is fulfilled by GRIPCOIL with highest loading capacity by means of thread reinforcement with its simultaneous low area requirement. Due to fewer connection points and a reduction in screw sizes, the saving of materials, size and weight with the same or higher requirements GRIPCOIL leads to a substantial reduction in costs.

– shorter female threads
– smaller screw with higher strength class

Fitting Stability

The outer diameter of the GRIPCOIL thread insert is larger than that of the tapped thread by a precisely calculated value in the non-fitted condition. This difference ensures, in addition to the inherent spring action of the GRIPCOIL thread insert material radial expansion, a stable, play-free positioning in the nut thread. Additional fixing elements adhesives – such as required for fixed bushes – are no longer necessary. For utilisation of hammer driven screws please consult our technical consultant.