VOSS Lok 40

Hydraulic tube connections with the highest quality standards - that is what we are known for around the world. So that is why it is important to us to continuously improve our solutions. Our development engineers have been moving away from cutting ring systems and toward forming systems in hydraulics for years. A seal and holding contour is formed on the tube end with the VOSS Lok 40 forming machine, which exhibits maximum leak-safety - even under demanding conditions - for instance when used in hydrogen and CNG-applications.

The result: VOSS Lok 40 – our innovative and cost-effective tube forming solution.

The VOSS Lok 40 tube contour

The 40° tube contour is formed at the end of the tube with the VOSS Lok 40 forming machine. The material on the tube surface is compressed and smoothed on the sealing radius by the mechanical forming process. This eliminates surface defects on the tube and achieves maximum impermeability.

The VOSS Lok 40 coupling system

Screw sockets and tube contours are aligned with each other in such a way as to achieve highest pressing of sealing surfaces and thereby an optimum seal of the only possible leak path.

  • Das Bild zeigt die thematische Darstellung des Verschraubungssystem von VOSS Lok 40
  • Das Bild zeigt die thematische Darstellung der Rohrkontur von VOSS Lok 40
  • Das Bild zeigt eine Zeichnung der Rohrkontur von VOSS Lok 40
  • Das Bild zeigt eine Zeichnung der Vermessung der Dichtflächen von VOSS Lok 40

Design-dependent process reliability

  • Error-free pre-assembly with mechanical forming process
  • Protection from assembly errors with noticeable increase in force at the end of assembly
  • Easy and safe torque assembly possible


High tightness

  • High precision tightness at nominal pressures up to 700 bar
  • Ideal for use in gas applications
  • Reduction of leak paths thanks to high finish quality of the forming 


Highly cost-effective

  • Prevention of leaks and claims
  • Reduction of material and storage costs 
  • Fast and more process-reliable forming process


The VOSS Lok 40 system can also be used in combination with conventional clamping ring screw sockets. The cost advantage as well as the reduction of leak paths remain, except the assembly advantage of the "soft" block stop cannot be used in this combination.

  • Das Bild zeigt eine Zeichnung der Kompatibilität von VOSS Lok 40 zu handelsüblichen Klemmring-Verschraubungsstutzen
  • Das Bild zeigt eine Zeichnung der Überwurfschraube von VOSS Lok 40

The VOSS Lok 40 male nut

In addition to the extensive variety of coupling bodies and screw-in bosses, we have also designed the VOSS Lok 40 male nut. Combined with a form drilling, it is a cost and space saving solution for crash-safe block integration. 

Advantages of block integration:

  • Screw-in boss is not needed
  • Reduction of leak path
  • Increased safety in the event of a crash
  • Space-saving installation area

The product range

The extensive VOSS Lok 40 system comprises a wide variety of structural shapes, such as angle, T or L-couplings. The system components are available in steel, stainless steel and various special materials with differing outside diameters.

  • The VOSS Lok 40 forming machine processes tubes with an outside diameter from 6 to 22 mm, as well as imperial dimensions
  • Suitable tube materials are steel, stainless steel, aluminum and special materials, such as CuNiFe
  • Coupling components made from steel, stainless steel, brass or special materials

Assembly made easy

  • Assembly is performed in just a few steps
  • A controlled increase in force occurs at the end of the assembly process
  • The option to re-tighten the connection is retained


Assembly advantages compared to clamp ring systems

  • The assembly travel path is significantly reduced (tightening 120° instead of 450°)
  • VOSS Lok 40 also enables torque assembly
  • The noticeable increase in force at the end of assembly protects against over-tightening
  • Das Bild zeigt eine Zeichnung des Übermontageschutzes von VOSS Lok 40
  • Das Bild zeigt die Darstellung des Montageweges von VOSS Lok 40 gegenüber Klemmringsystemen