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... . . more than 60 years of experience

Those who have followed the development of Fey laminar rings since 1946 will remember that laminar rings were first produced in Germany in a single wound version. The "FK2 AS" was used to equip previously used pistons in internal combustion engines to reestablish the sealing or the compression in oval and "worn out" cylinders. These laminar rings were made from spring band steel or flat wire, including stainless steel and high-temperature alloys.

This first application of the Fey rings was successful for many years, however, it could not secure the economic future of Fey.

A significant condition for the further development of the Fey laminar ring sealings was the development of a cost effective manufacturing process, so that the rings could be manufactured individually in an oval format through thermal treatment, becoming round when installed in their working conditions as out-springing rings into bores or as in-springing rings on shafts by providing the highest possible gap sealing.

Using these arguments and the positive sealing effects of gap and labyrinth sealings, Fey was in a position to address the sealing problems of the industry and this resulted in increasing inquiries and requirements that led to a sealing program with a diameter range from 15 mm to 1,300 mm. In the meantime, Fey's manufacturing program consists of app. 16,800 ring types with different ring diameters, ring cross sections and different ring materials.

Successful users of Fey laminar rings include manufacturers of roller and plain bearings, exhaust pipes of internal combustion engines, axle bearings of rolling stock, continuous casting plants, transmission systems, power units and many more.

General information

Fey laminar rings used as sealing elements for rotating and static sealing applications:

Fey laminar rings combine a low contact multiple labyrinth with very little gap width and are especially effective for grease sealings and for the exclusion of fluid media, dirt and dust entry as well as other contaminations. In addition to their outstanding sealing characteristics for rotating components, the low contact laminar rings with low friction produce a significant reduction of internal heat and wear, which qualifies these sealing elements for high speed applications and applications in temperature and/or friction sensitive installations.
For static sealing applications such as axial compensators at screwed exhaust manifold systems for internal combustion engines, exhaust gas recirculation systems and power units with operating temperatures of up to +700°C, Fey laminar rings will be manufactured from chrome nickel materials, which are spring and heat resistant in the sealing area even at high temperatures.

Design types include single wound (FK3) and double wound (FK6/FK5/FK5-HFL) laminar rings:

Fey laminar rings are offered as single wound laminar rings (AS and IS) with joint gap and as double wound laminar rings (ASD and ISD) without joint gap. The use of the different laminar ring geometries and the design of the installation technology depend on the operating conditions, the motion sequence of the components to be sealed and on the leakage requirements of the customer. In addition to single outspringing or single inspringing ring sets, Fey laminar rings can also be combined as a ring set within a groove: outspringing rings with inspringing rings and vice versa. The additional coverage of the groove base plays within the bore of the housing or at the groove base of the shaft optimize the labyrinth effect and therefore the sealing effect. However, we must point out that these combinations cannot be recommended for all sealing tasks.

One thing which must be avoided at all costs is that the laminar ring seal sets are moved axially by the movement of the groove, which may result from the axial play in the bearings. Depending on the frequency involved, friction would be generated between the ring and the groove flanks which may lead to premature wear of the rings and adjacent components.


This web site cannot show all potential applications for the laminar rings. This is why we refer to the questionnaire. The answers may put us into the position to address your sealing issues and to proposes appropriate recommendations.

Run and installation tests:

Run and installation tests under operating conditions must be performed in each case before standard production can begin to determine, whether the desired sealing effects for laminar sealing rings or the retaining effects for laminar retaining rings can be achieved. We recommend to contact our technical office for clarification.




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