Stamping & transformation

Our portfolio includes fine blanking presses from 400 kN to 5,000 kN. We process material thicknesses from 0.3 mm to 14 mm.

The following tool technologies are in use

• Combination tools
• Follow-on composite tools
• Follow-on composite tools with displacement technology

In the manufacture of closed rings using stamping processes, material use is a significant cost factor. In some cases, only 10% of the strip material would be able to be used.

KERN-LIEBERS pursues a material-saving approach in which flat strip is bent endways into a ring by means of a rolling process. After separation, the ring is closed using a welding process (laser welding or resistance welding).

For the subsequent processing that then takes place, the full range of KERN-LIEBERS production technology is available. Fine blanking and stamping can be used to create complex interior and exterior geometries including hole patterns. The profile can be changed by collar forming, setting or embossing operations. All precision machining and heat treatment processes are available to finish the parts.

KERN-LIEBERS specializes in the production of precision sleeves, with an approach centered on transformation processes. Instead of complex machining operations on solid material blanks, we use rotary swaging. To give an example, a pre-punched blank is formed into the finished dimension or close to the final contour depending on the tolerance and geometry requirements.

In the rotary swaging process, the material is hammered around a mandrel by high-frequency single strokes, with the inner mandrel forming a negative of the contour in the part. The level of precision is excellent, so that expensive superfinishing processes such as honing, internal grinding, etc. can sometimes be omitted. In addition to rotationally symmetrical internal shapes, asymmetrical internal geometries can also be produced.

The process is particularly useful for expensive materials such as stainless steel, heat resistant steels, non-ferrous metals, etc. because only one machining process is required to finish the face in many applications. The feasibility of production can be demonstrated in advance by computer-aided simulation of the transformation.