State-of-the-art methods for customized quality.

Development skills

Our toolmaking department develops and builds both simple stamping tools and highly complex fine blanking, follow-on composite and stamping and bending tools. CAD and software tools such as collision control software support our design engineers in the creation of tools and the parts handling and integrated control systems that go with them.

As a component manufacturer, one essential element in our productivity and efficiency is the ability to shape the manufacturing process for our products through the combination of optimum process steps. For each new product, we define the required process steps and develop the production facilities to implement them. We develop our own machines and modify standard machines according to our requirements. In addition to the central production processes, we also integrate the accompanying processes. Market success, as with strip springs, is based on these central standards.

We start with our low-cost mass production processes, such as stamping, fine blanking and stamping/bending, and develop them until they push their technical limits. We do this with the help of modern simulation tools to better understand the processes.

When component requirements cannot be met with our mass processes, we deploy our precision machining processes. We have a wide variety of production processes for milling, drilling, turning, grinding and honing available to us. An extremely well-equipped heat treatment department completes the range of services we can offer. To ensure an economic and high-quality manufacturing process, it is important to ideally coordinate the individual manufacturing steps and to define limits for the process.

Our technology experts are continuously developing our processes so that we can implement sophisticated mass production solutions. Our expertise is systematically recorded in our FMEA system. Even at the risk analysis stage, we are already able to make informed statements about the feasibility of manufacture.

Working closely with the customer, KERN-LIEBERS provides professional support during the product development phase. We use 3D CAD software to adapt draft designs for parts to be developed to KERN-LIEBERS production technology. To meet requirements regarding load and service life, we use powerful FEM calculation software.

In the resulting parts drawing (customer), all tolerances are closely examined in terms of economic producibility. The drawing is optimized to ensure that as many additional operations as possible can be omitted or replaced by more cost-effective manufacturing processes.

To test the individual parts or assembly designs resulting from this process, we can quickly produce prototypes. For important functional dimensions, we also make targeted use of overall tolerance fields to limit sample testing.

Forming processes such as bending and stamping, fine blanking and normal stamping are calculated, analyzed and optimized using numerical simulations. Development times and costs for production tools are reduced, as is the cost of testing and optimization.

With this approach, KERN-LIEBERS helps to keep costs for new developments as low as possible. And the time "from prototype to standard part" is minimized too.

The characteristics and costs of a product are determined early, in the development phase for a product. That's why is a production-oriented design of each individual component in a product is of crucial importance. With the wide range of manufacturing options available to us, we are able to incorporate the specific advantages of each separate process into the product development process.

Before we create tools, the forming processes are simulated in detail. One very interesting by-product of this process for the customer is that we can provide the result of the simulation, with the geometric particulars (indentations, die marks, burrs etc.) and the material-specific properties (hardening, residual stress, microcracks etc.). Before our customers receive hardware in the form of samples, they can incorporate the simulation results into the overall product.

With our prototype engineering, we are able to produce prototypes. Our customers can already test the first close-to-production prototype samples during the development and testing phase.

A big plus here is that the technologies and expertise of the entire group of companies is available to draw on. Our experts work closely together in this area.

The technologies include

  • Wire and die sinking
  • Laser and water jet cutting
  • CNC stamping and bending
  • Embossing, stamping, fine blanking etc. in sample frames and in production and test presses
  • CNC milling, turning and grinding
  • All common heat treatment processes and special hardening processes
  • Vibratory finishing
  • Honing
  • Ceramic shot peening
  • Wobble riveting, hot riveting, caulking
  • Laser welding


The KERN-LIEBERS group calculates the optimum spring dimensions based on customer data (customer requirements) using specially developed in-house spring calculation programs.

The goal is to determine the optimum type of spring and spring dimensions in terms of function and cost.


  • Calculation of compression, tension and torsion springs in accordance with DIN EN 13906-1 to 3 and quality specifications DIN EN 15800, DIN 2097 and DIN 2194
  • Spring optimization
  • Fatigue strength calculation, e.g. Goodman
  • Analysis of vibration behavior
  • Assistance with spring design for constantly stressed parts

The complex demands placed by our components on the materials used – mostly special steels – mean that we need to work closely with our suppliers to develop customized solutions. From the definition of analyses and manufacturing processes through to testing in our own laboratory and continuous monitoring of the quality of the products we ship, we keep track of the materials used at all times.

Equally important are the continuous development of the range of materials used in production, and finding new potential supply sources and material variants. By keeping track of market developments in new high-performance materials and with our commitment to research projects, we lay the foundation for future KERN-LIEBERS products.

Filling simulations can be used for the thermal and rheological design of tools for the processing of thermoplastics, thermoset materials and elastomers. We can use these simulations to obtain information on the processing parameters that will later be used in the process. They also provide us with information about distortion behavior, the location of weld lines and the fiber orientation of the fillers.

Ideally, these simulations should be carried out early, in the product development phase, to ensure that the subsequent manufacture of the components is cost-effective. As part of product or process development, KERN-LIEBERS is able to incorporate the findings of simulations of this kind.

We use powerful FEM calculation software in the development of stamped and fineblanked parts.

Forming processes such as bending and stamping and fine blanking and normal stamping processes are calculated, analyzed and optimized using numerical simulations.

This shortens development times and reduces the cost of testing and the optimization of tools.

In addition to the shape and functionality of a product, a design appropriate to the material or the stresses expected is of crucial importance.

To facilitate this, we use appropriate material models to analyze stress-strain behavior as a function of the component geometry, stress type and operating temperature. FEM structural analyses during the design phase allow us to make very early predictions about the stresses the components will be subjected to and the expected component behavior. Shorter development times and highly targeted prototype tests lead to reduced development costs.

Industry applications


Electrical engineering

Building services engineering

Consumer goods

Mechanical engineering and equipment manufacturing

Medical technology