HELICOIL® classic

  1. Bollhoff Armstrong >
  2. HELICOIL® threaded inserts >
  3. Product types >
  4. HELICOIL® classic

The Classic threaded insert – HELICOIL® classic

The original classic 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.



HELICOIL® plus thread inserts

The original classic 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 in the installation tool prior to installing and then when it is in position and the tool removed it expands, like a spring, to fit precisely into the threaded hole providing a hardwearing screw thread with the greatest tensional strengths higher than the original tapped hole.


  • Corrosion and heat-resistant
  • Wear-free
  • Reject recovery
  • Uniform load and stress distribution
  • Easy identification even when installed (colouring or surface treatment)
  • Available in different variants for very different requirements
  • Assembly systems, tools, and products available from one source

HELICOIL® thread inserts are available in metric and imperial dimensions.


free running

HELICOIL® free running

Every thread of the thread insert with precision formed, rhombic profile is free running. The result is an internal thread true to gauge that can be used on both sides.

The green colour allows easier identification when the HELICOIL® free running is installed.

Our 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.


HELICOIL® screwlock

The HELICOIL® screwlock bears the same benefits regarding threads as the HELICOIL® free running.

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 screwed-in 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.


  • HELICOIL® application

    Machines and plants

    Machine construction console ,
    Material G-AISi9 Mg,
    HELICOIL®, M 8 x 12,
    free running

    For use in printing presses, in high temperature range, for repeated screwings, maintenance and repair

  • HELICOIL® application

    Electronics, sheet metal, plastic

    Carrier plate for electronic components made of aluminium pressure die-casting

    For use in lamps, electrical appliances, drill hammers, etc.

  • HELICOIL® application

    Automotive & aerospace

    Car gear box cover made of aluminium die-cast,
    HELICOIL®, M 14 x 1,5 x 14, free running

    For use in gear boxes, exhaust systems, engines and satellites, for thread reinforcement, repeated screwing, maintenance and repair

Download Version Language Type/Size Add
The Blue Book
Aerospace Buyer’s Directory
To HELICOIL® Wire Thread Inserts
2016 English PDF / 522 KB Add to download
HELICOIL® classic
Thread technology for high-strength fastenings
2014 English PDF / 8124 KB Add to download

When you have finished selecting your catalogues click here to download!

Installation process of HELICOIL® classic

HELICOIL® free running – thread insert

HELICOIL® screwlock – thread insert


Copyright © 2013 Bollhoff Armstrong LimitedSEO by Rocketfish Ltd