Production facts about the plant

The Cotarko GmbH plant in Cologne currently employs 280 people.

With a production volume of about 30 million parts and material consumption of 54,000 tonnes a year, about 130,000 parts are currently delivered to customers worldwide on a daily basis.

A total of 4 Hatepur forging presses, 3 wedge and 4 ring rollers presses such as 24 machines for machining ensure that around 130,000 forged parts are delivered to our customers worldwide every day.

Technical highlights

Commissioning of the worldwide first Hatebur AMP70L machines for extruded components – Development of the first extruded component for AMP70L

Manufacturing of ,ring gear‘ differential components with an AGW ring rolling machine

Utilization of Smeral ULS 100 cross wedge rolling for transmission shafts

Commissioning of one of the world‘s first Hatebur AMP50XL machines for extruded components

Restructing of plant layout according to the principles of “lean manufacturing”

Start of machining for forging blanks as as an additional process step

Launch of the internal wheel hub manufacturing and assembly line

Launch of our new internal toolshop

Fast forging presses

High-tech industrial forge for precision forgings

The forging of steel parts is carried out in the temperature range from 1100°C – 1250°C. The bar stock is heated inductively to the suitable forging temperature, sheared in the Hatebur and then pressed in four forming stages. In the through-feed process it is possible to carry out controlled cooling from the forging heat.

Machinery: Hatebur



Forming stages
Deployment weight
max. Ø forging
Stroke number
Total press force

AMP 50 (XL)
1 machine


up to 2,0 kg
about 104 mm
8000 kN

AMP 70 (L)
2 machines 70
1 machine 70 L

up to 5,0 kg
about 150 mm
12-15000 kN

Special features:

  • The AMP70 has an 180 mm ejector stroke for extruded parts
  • Extruded parts can also be produced on the AMP50

Wedge rolling

Producing for gear shafts

Compression forming of rotationally symmetrical blanks at 1100°C – 1250°C between counter-rotating moving generating tools, which reduce by rolling on the surface of the workpiece. Preferred process for manufacturing gear shafts with widely diverging geometrical cross-sections.

Machinery: Smeral wedge rolling


Roller diameter
Forming force
Torque coupling
max. Ø for rolling

3 machines

1000 mm
13000 kN
7800 kN
100 mm

Special features:

  • Forming with undercuts is possible in this process
  • Distortion after machining (hardening) is low
  • Homogeneous grain flow through whole shaft

Ring rolling

Producing for seamless ring gears

The ring roller process is realised as a combination process in the temperature range of 1100°C – 1250°C. A process combination of blocking and radial and axial rolling permits seamless production of complex ring gears for the gear differential.

Machinery: maxi-press, multi-pin radial roller and axial die-forging roller


max. Ø forging
max. forging height
Rolling force
Revolutions per roller

3 machines

16000 kN
280 mm
80 mm
1250 kN

Special features:

  • Rolling blanks can be designed with low allowance as finished part
  • Especially good surface quality through rolling process
  • Unfinished surfaces = finished surfaces can be taken into account on the product
  • Environmentally friendly process thanks to low material use

Heat treatment

Different treatment processes according to your specifications

The workpieces are heated slowly and thoroughly in all annealing processes. The various processes which serve to set the desired material properties for use or prepare for subsequent processing (forming or machining) differ through:

  • Annealing temperature
  • Annealing duration
  • Type of cooling
  • Sequence of different heat treatment steps

The component characteristics regarding hardness, strength and grain spacing quality are guaranteed by the various heat treatment processes in cooperation with our customers. We can offer the following processes:

  • Normalising
  • Quenching and tempering
  • Annealing
  • BG-annealing
  • Controlled cooling from forge heat

Mechanical processing

Complete production line for machining

Under certain circumstances, the stage in the process chain at the end of which the precision part the customer wants is ready, may not yet have been reached with the various forming technologies. For this reason, Cotarko has made large investments in machining processing technology.

Machinery: Emag, Rasoma, Karl Klink, Chiron





24 machines

Gear wheels (Pre-machining)
Shafts (Pre-machining)
Wheel hubs (ready-to-install)

Wheel hubs (ready-to-install)
pressing, crack testing

Special features:

  • Complete production line for machining, especially in wheel hub production
  • Pre-machining of gear wheels and shafts is possible in our company
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