We manufacture and supply Lock-Nuts according to DIN specifications and individual requirements, in sizes M4 to M110 from a variety of materials. For extreme-strain applications we recommend our FS® All-Steel Lock-Nut.



Fastening problems with dynamically highly stressed threaded joints have lead to the development of the FS® All-Steel Lock-Nut. It has a flexible and completely threaded locking element which is fitted into the nut body.

As opposed to competitors’ lock-nuts, the FS® All-Steel Lock-Nut can be used universally. This is due to the fact that the design combines all elements required for a safe threaded connection, such as re-usability, heat resistance, corrosion resistance, protection of the counter thread and narrow tolerance of the locking torque.

The FS® All-Steel Lock-Nut can be reused many times without significant loss of its locking capability and exceeds, after 15 times of tightening and loosening of the nuts, the values given in DIN EN ISO 2320.

Flaig + Hommel is recognized, worldwide, as a manufacturer of the FS® All-Steel Lock-Nuts and, since the 1950s, as a reliable and innovative partner of the automotive and rolling stock industries.

Base Use

  • The FS® All-Steel Lock-Nut offers double-safety. The locking element works both in radial and axial direction. Thus the locking effect remains fully operational even after repeated unfastening of the FS® All-Steel Lock-Nut.
  • The FS® All-Steel Lock-Nut locking element, which is offset but otherwise conforming to standard thread sizes, prevents the counter thread from being damaged.
  • Economical storage due to universal use.



  • Reliable even in difficult screwed connections such as used in turbochargers, exhaust manifolds, catalysts, highly stressed gearboxes, superchargers and vibrating machine components.
  • The FS® All-Steel Lock-Nut has proven itself over many years and has created a host of new possibilities to crack old problems (new solutions to old problems).

Assembly Advantages

  • Cost- and space-effective automated assembly instead of castellated nuts, split pins, counter nuts, etc.

Technical Advantages

  • The clamping force is adjustable during manufacturing within fine tolerances.
  • The FS® All-Steel Lock-Nut can withstand temperatures up to 1000 °C. For use within temperatures in excess of 300 °C, suitable heat resistant materials are being employed depending on the application.
  • High axial loads are granted as threads are manufactured to DIN EN ISO 2320 standards. The nut measurements meet the requirements of the standards DIN EN ISO 7042 / DIN EN ISO 10512, DIN 6925, DIN 980 M and DIN 6927 /DIN EN ISO 1667 / DIN EN ISO 1664 (flange nuts). Special designs with reduced height are available. Please talk to our engineers.

The FS®-All-Steel Lock-Nut are resistant to high temperatures and corrosion due to Flaig+Hommel’s use of modern technologies, resulting in better reliability than galvanizing. These techniques have been accomplished without inducing hydrogen embrittlement.

Please send us your inquiry

We look forward to your product-related inquiry. Our sales department will check your request and contact you promptly.


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