Modular Construction - Highly Flexible

ALFING Crack and Assembly Modules for Small and Medium Quantities

ALFING crack and assembly modules were specifically developed for the cracking and assembly of connecting rods in smaller and medium quantities. The hand-loaded modules allow for all process sequences through their modular structure. The same technologies and equipment are used within the modules as with the fully automatic ALFING rotary transfer machines.

Standard Processes Include

  • Making stress riser by laser
  • Cracking
  • Bolt assembly
  • Bushing insertion
Conrod machining without tool change


  • Flexible machine for low to medium batch sizes
  • Cycle time of approx. 20 seconds
  • Short changeover times through changeover flexibility
  • High-speed crack equipment with process monitoring guarantees excellent quality during the cracking process
  • High quality during bolt assembly with the use of torque-controlled electric nut runners from ALFING (AMT)
  • Location-oriented bush assembly with servo controlled pressing spindles and integrated process monitoring
  • Recording and analysis of all important process parameters
  • High operator and maintenance friendliness

Laser Stress Riser Setup

Laser Stress Riser Setup

The pre-requisite for a precise fracture is the quality of the previously made fracture notch. Predominantly lasers are used to create this notch.

The newest generation of fiber lasers are used in ALFING machines.

  • NC – controlled laser head
  • Possible depth of the laser notch up to 1mm
  • Laser notch possible with any shape (straight, arched, etc.)
  • “Perforation” possible

Cracking Mandrels

The cracking mandrel is the component that decides the quality of every fracture machine. If there is a lack of experience, a lot of bad things may happen here. The result could be unclean breaks, break outs, strong deformation or partial breaks.

This cannot happen with cracking mandrels from ALFING. Due to our decades of experience and our high-speed crack equipment, we have the perfect solution for every connecting rod size and every material. Process monitoring that informs the user of the quality of the crack process at any time is also available if desired.

  • Hydraulically activated wedge system
  • Robust separating system
  • Hydraulically activated cap support with fine adjustment of the gap
  • Hydraulically activated support on the rod side and/or adjustable fixed pin inside the pin bore
Cracking mandrels

Bolt Equipment

Bolt equipment

The bolts are inserted manually or optionally automatically and are pre-tightened. In the next step, the bolts are slightly loosened again and a vibrating unit can be activated to remove any loose particles from the joint faces. The final step is the tightening of the bolts with a defined torque.

Bush Insertion Equipment

The bushes are inserted automatically and - if necessary - aligned before insertion. The bushes are inserted with a servo pressing spindle with simultaneous monitoring of the insertion force and insertion depth.

The bush may also be calibrated.

Bush Insertion Equipment



Connecting rods are highly stressed components and subject to permanent technical development.

With our modernly equipped testing area, we support our customers during different phases of development:

  • Checking the cracking properties
  • Preliminary tests to determine the optimal parameters for the “laser notch” and “cracking” processes
  • Manufacturing of prototypes for engine tests



Alfing Support Service



AMT Support Service