Smart Fluid Systems


Part of our core competence is the bending of cables. COHLINE has the optimum process in-house for every application. In total, more than 100 bending machines are in operation in the COHLINE Group.

The choice of bending technology is influenced by a variety of factors.

  • For special items that are produced in very large quantities, we use specific automatic bending machines, most of which have been developed in-house.
  • Our CNC bending machines in the various performance classes are universal for medium to large quantities.
  • Some of the CNC machines are also equipped with robot handling.

Depending on the bending geometry, hand bending tools are still used today, as this is in some cases the only technical solution for a bending requirement. To ensure process reliability, hand bending tools can also be designed with sensory monitoring.

Tube end forming (upsetting/flanging)

Tube end forming is another core process at COHLINE. We have extensive know-how in the cold forming of tube parts. As a rule, connection fittings molded directly from the tube are significantly cheaper to manufacture than fittings soldered on.

From simple standard hose seats, to special hose seats for extreme requirements, to complete connection components with sealing seats and fastening elements or high-pressure sealing heads, we can mold a large number of geometries in different materials.


Soldering  is one of the most effective joining methods for securely and tightly joining fittings and pipe parts. COHLINE is an expert in soldering technology.

The following soldering processes are used in the group of companies:

  • High temperature soldering (>1,000 degrees) in continuous furnaces. Used for steel and stainless steel components. Due to the inert gas atmosphere, no flux is required
  • Flame brazing - mainly for aluminum lines
  • Inductive soldering

With 8 continuous furnaces and more than 25 aluminum flame soldering systems, we have sufficient capacity.


COHLINE has relied on automation for decades.

In tube end forming as well as in bending processes, automated processes are preferred wherever it is economically or technically feasible. COHLINE has many years of experience in the design and construction of automated production equipment.

Plastics Processing

The development of plastics with ever higher performance has continued unabated for years. In terms of temperature resistance, oil lines in vehicles made of specially modified types of polyamide can be used to replace conventional metal lines with elastomer hoses. The use of plastic connectors or other connections is also possible.

At COHLINE, we have extensive expertise in plastic pipe forming. The special polyamide tubes are extruded in-house.

Connection fittings can be welded on with precise process control or joined purely mechanically.


To prepare steel or stainless steel pipes for the brazing process in the continuous furnace, welding and tack-welding processes are used, among others. In this process, attachments such as holders or flanges are tack-welded to the pipe parts by means of resistance welding. In special cases, it may also be advisable to weld the attachments on completely. Particularly in the case of aluminum pipes, welding is sometimes an alternative to soldering. Various welding processes such as TIG, MIG or MAG are used. But welding is also an issue for plastic lines. At COHLINE, for example, O-ring sockets are connected to the PA pipe by means of friction welding in special rotation welding systems.