Manufacturing skill

GMN manufacturing technologies are optimized to meet the requirements of high-precision ball bearings and complex bearing systems.

Prototype manufacturing

Prototype manufacturing under production conditions

A significant part of the GMN philosophy is the manufacture of prototypes under production conditions. This way, identical quality is guaranteed at the start of series production right after the product has been released.



Precision processing of bearing rings

For precision processing of bearing rings GMN has a group of machines optimized for series production of high-precision ball bearings.

Surface quality and geometry are always the focus of optimization processes, so that standard series as well as special bearings can be manufactured to the highest precision standards.

Special designs:

  • Thin ring bearings
  • Flange bearings
  • Special dimensions


  • Chrome steel (100CR6)
  • Stainless steel
  • HNS steel (High Nitrogen Steel)
  • Heat-resistant steel

Precision processing of shafts

The know-how and machines used for spindle manufacturing are used for precision processing of shafts. The grinding of cylinder surfaces and ball races are standard processes.

Important quality characteristics:

  • Dimensional accuracy of the parts
  • Shape and position tolerances
  • Surface finishes


In particular, when very high rotational speeds are required, the balancing quality of the rotating components determines the functionality of the final product. Therefore, many components at GMN are finely balanced depending upon the application.

Precision processing of modification parts

For many application areas such as medical devices, laser or measurement equipment, more complex bearing systems are developed and offered in addition to ball bearings.

The precision of modification parts such as bearing bushings and housings are fundamentally important for the function and precision of systems down to the micro range.


The tools and fixtures required for the production and assembly are produced with tools that have been specially designed for GMN machines and the product spectrum.

KL_ENG 101 GMN F_935x550



Measurement equipment

The precision measurement department performs all measurements of precision parts as a neutral service provider. This is done in received goods, on-going manufacturing as well as service investigations for bearing analyses.

Among other things, standard inspections and measurements include:

  • Hardness and joint tests
  • Topography analyzes (surfaces)
  • Shape and position tolerances
  • Coordinate measurements (2- and 3-D measurements)

The reference standards are regularly compared with those of the Physikalisch-Technische-Bundesanstalt [Physical Technical Federal Technological Institute] (PTB). Of course, the fine measurement area is completely air conditioned and sound-isolated.

Product-related measuring devices are developed, built and tested in our separate testing and measurement facility.



Smooth interplay of people, material and systems provide ready-to-install components from one source – at a level of quality which meets the highest expectations.

You benefit from:
  • Experience in the design of demanding bearings
  • Experience in handling complex systems
  • Optimized measurement and assembly technology
  • A wide range of joining techniques for assembly and assemblies
  • Final assembly of the systems under the best conditions
  • Continuous process and component testing
  • Experience in handling, storage and packaging of components for high-vacuum applications
  • Simplifying logistics at the customer by supplying complete assemblies

PVD coating



Using its own PVD (physical vapor deposition) sputtering system with a coating chamber optimized for roller bearing applications, GMN has been coating components for various application areas since 1996:

  • Medical devices (dry lubrication)
  • Vacuum technology (dry lubrication)
  • Laser technology (protection against aggressive gases)
  • Aerospace
  • Safety bearings (bearing-supported lubrication)

For example:

  • Bearing rings
  • Shafts and axles
  • Cages
  • Spheres


Various high-purity materials (targets) are used as adhesive or functional layers depending upon the area of application:

  • Silver (Ag)
  • Lead (Pb)
  • Gold (Au)
  • Molybdenum disulfide (MoS2)



Material brackets are individually fitted in order to efficiently coat three-dimensional surfaces. Technological know-how and our experience in PVD coating form the basis of many of our developments and products.

  • Uniform layer thicknesses of the highest adhesive strength at high growth rates
  • Layer thicknesses from a few nanometers (10-9 m) to a few micrometers (10-6 m)
  • Layer thickness fluctuations in the nanometer range (10-9 m)
  • Technical equipment for sputtering several materials simultaneously (co-sputtering)
  • High process stability as fully automatic
  • Application of layers without exceeding a critical temperature of the substrate


The components are cleaned in multiple process steps before PVD coating or as final handling for vacuum applications:

  • Ultrasonic cleaning
  • Degreasing
  • Vacuum drying
  • Plasma cleaning

For many applications, an additional cleaning of the components is required.



GMN uses cutting-edge high technology to analyze layers. Layer thickness measurements in the nano range and analysis of coating materials are necessary and helpful measurements for high-end bearings used for medical devices and ultra-high vacuum equipment.

  • High-precision and programmable XY (Z) measuring table
  • Analysis and layer thickness measurement of very thin individual layers and layer systems
  • Analysis of the basic material through a coating system
  • Autofocus or visual focus