A new cutting ring system from VOSS Fluid

A cut above the rest

Application example: small truck with lifting platform.
Application example: small truck with lifting platform.

The perfect cutting ring tube fitting is reliable when it comes to leaks and processes and offers maximum load and pressure resistance, while preventing system-immanent assembly errors – such positive features having been long-awaited by so many users. VOSS Fluid has now brought out a solution that combines all these advantages in a single cutting ring system, enabling even inexperienced fitters to achieve precision work.

Cutting ring systems guarantee safety. They ensure leak-free tube connections in hydraulic systems. Well at least in theory. In actual fact, a process-reliable fitting almost always depended on the fitter’s experience and concentration. To overcome these less than adequate circumstances, VOSS Fluid has developed an assembly-reliable system: the VOSSRingM with VossRing pre-assembly stud. The patented solution for connecting steel and stainless steel tubes is easy to handle and enables even inexperienced or fast-turnover personnel to achieve 100% precise pre- and final assembly.

Leak-free and process-reliable cutting ring system: VossRingM with VossRing pre-assembly stud.

The Ring of Rings

The basis of the intelligent solution is the VossRing. The optimized twin-cutting technology, ensures a perfect indentation and firm fit at the tube, even for thin-walled tubes. The stable cutting ring cross-section along with other geometric details guarantee the highest pressure resistance and dynamic load bearing capacity. That means the ring can withstand pressures of up to 800 bar at a fourfold safety factor without any problem. FEM-optimized rounding of the cutting ring reduces the risk of damage to the stud and effectively prevents the tubes from rotating during assembly.

Process-reliable pre-assembly with limit stop function

Yet completion of the VossRing did not mark the end of the project. «What use is the best ring – states Gerd Berghaus, Product Developer at Voss Fluid – if the error sources during assembly can be as diverse as the people installing it?» To eliminate this safety gap with an effective design, the company has developed a highly reliable assembly tool: the VossRing pre-assembly stud. The solution prevents assembly errors by signaling the exact end point of the pre-assembly to the fitter via an unmistakable increase in force. Once the assembly is completed, the stud comes into contact with a definite locating surface at the end point of the ring.

Hydraulic installation on an MBB-Palfinger lifting platform: interaction of tubes with Voss cutting rings and couplings as well as hoses.
VossRing for a perfect indentation along with maximum pressure resistance and dynamic load bearing capacity.

This means the assembly process is finished at the optimum point – an excessive assembly is effectively prevented. Besides the highest level of safety, the new stud also makes the fitter’s work easier: The sophisticated geometry of the tool in the tube limit stop range reduces the final assembly route from 90° to 30°, thereby decreasing the work to be performed by the fitter by around half. This advantage is especially apparent under difficult installation conditions.

Maximum precision

The VossRing pre-assembly stud consists of high-performance steel, which does not wear like conventional standard tools, in addition it’s tool service life is 20 times longer. These properties make wear inspections totally superfluous: Although normal pre-assembly studs have to be inspected regularly for proper functioning owing to flaring of the cone contour, this negative property is absent from the VOSS tool. Upon reaching the application limit, the stud breaks – thereby effectively preventing assembly errors due to tool wear.

The new cutting ring system allows even inexperienced fitters to perform precision work.

Corrosion protection

The 100% effective design of the new cutting ring system regarding safety, load bearing capacity and durability can also be seen in the unique surface quality of the cutting ring. «The zinc and nickel based coating VOSS coat-BLACK combats even aggressive media and therefore guarantees the high corrosion resistance expected by the customer», explains Berghaus. As a result, this surface not only attains corrosion resistance class K5 according to VDMA standard sheet 24576, but also exceeds the required resistance values against white and red rust both under laboratory conditions as well as in more demanding practical tests.


The new cutting ring system ensures leak-free and process-reliable tube connection with maximum pressure resistance and load bearing capacity. Assembly errors are reliably prevented by the patented limit stop concept. The shorter final assembly route reduces the required force and makes the fitter’s work easier – even in constricted installation spaces. That makes the system highly reliable and user-friendly.