We manufacture nuts in the DIN dimensions M5 to M110. Also special nuts by design; all-steel lock-nuts; high temperature resistant lock-nuts; ultra-light lock-nuts; hot-dip galvanised all-steel lock-nuts; standard nuts.

FS®-All-Steel Lock-Nut
Competent reliability even under extreme pressure!

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-locknuts and, since the 1950s, as a reliable and innovative partner of the automotive and rolling stock industries.


  • 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®-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.


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



  • 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.



  • 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).


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


The all-round lock with ratio-effect:
Weight saving up to 50%

The new FS®®-E All-Steel Lock-Nuts Economic and Ultra-Light are the solution to all applications where light, safe and high temperature resistance are required.

The new lock-nuts offer optimum safety even under dynamic loads and thus are ideal for application in the automotive-, aerospace-, wind energy- and bridge building industry.

Due to their small width across flats, a further weight reduction has been achieved in the Ultra-Light version, which makes a valuable contribution to CO2-emission reduction.

The FS®-E All-Steel Lock-Nuts Economic and Ultra-Light are one-part all-steel locking systems. The innovative principle insures that the clearance commonly seen in traditional screwed connections is removed.

It is comparable to the effect that can be observed between a nut and a bolt when a pre-stressed nut is tightened.

The clever thing about it is, that the locking effect continues working even when tightened. The flank surfaces operate like a pressure spring against the thread direction of the bolt. This results in an all around safety-effect comparable to the effect a brake caliper has in a disc brake.

The thread flanks of the bolt are enveloped on the whole 360° by the FS®-E All-Steel Lock-Nut. The FS®-E All-Steel Lock-Nut Economic and Ultra-Light are available with and without flange. Upon request they can also be supplied with movable flange or with FS®-UltraLock®-anti-rotation lock



  • One-part lock-nut especially designed for the automotive industry and related applications
  • Available in steel grade 8, 10, 12, 04, 05 and stainless steel grade A2, A4
  • Innovative operating principle with active locking effect – even when tightened.
  • Cost-effective solution for high-volume applications.
  • All-around safety effect similar to a disc brake effect.
  • Prevailing torque and mechanical properties according to DIN EN ISO 2320.
  • 360° locking effect – evenly distributed surface pressure, therefore very low seizing tendency on application.



FS®-E Ultralock is a mechanical principle based on an inclined plane with movable flange (wedge plate) which, combined with an all-steel safety element (prevailing torque), compensates relative movement below the lock-nut.

The release torque, resulting from the relative movement, does hereby not lead to a loosening of the nut. On the contrary. The pre-stress within the lock-nut increases and with it the connection’s breakaway torque.

In short: Breakaway Torque > Clamping Torque

Upon request we will supply standard nuts.

Please refer to our minimum order numbers.

At Flaig + Hommel we manufacture special nuts according to technical drawing or standard nuts in the sizes M4 to M110.

We use a variety of materials with different stability as well as various surface coatings. New products are ideally conceived in conjunction with the client in order to achieve optimum results regarding cost effectiveness and quality.

Features of special nuts are for example:

  • Nut with integrated washer
  • Eccentric arrangement of washer and thread
  • Individual key holds such as two flats, square, octagonal or double hexagonal
  • Extremely flat or high models
  • Contours with knurl, flange or supportive nose



  +49 (0) 7424 962 - 0