At the same time, the cost-effectiveness of the components used in their manufacture must not be lost sight of. Workpiece costs should be kept as low as possible without compromising quality. Here, Heidelberger Druckmaschinen works with partners who contribute to holistic process and cost optimization, such as Arno Werkzeuge, a manufacturer of cutting tools for turning, grooving, drilling and milling.

Harald Johann, Head of Work Planning Cams, Gears and Model Parts, and Andreas Knopf, Technologist Turning and Tools at the Wiesloch-Walldorf site near Heidelberg, are responsible for the production of gears for offset printing machines, among other things. During the integral examination of the existing production process for gears, the indexable inserts in the turning process were also examined more closely. These can be an important cost-reducing factor when it comes to increasing tool life: Multiple tool lives and the resulting reduced change and calibration times quickly add up to a significant amount in terms of unit costs over a longer period of time. With the aim of optimizing tool life in mind, Andreas Knopf and the Arno application engineer tested the internal boring and finishing of cast steel gears with the TCGT16T308FN-ALU AL10 high-positive indexable insert. Arno Werkzeuge defines high-positive as indexable inserts with a rake angle of 27°, which are peripherally ground and have a polished chip breaker, meaning they have a sharp cutting edge and require only minimal cutting forces. The surface quality produced is correspondingly good and the results highly precise.

100% increase in service life

The machining experts from both companies worked together to check a wide variety of turned parts and tested alternative indexable inserts from Arno. Among other things, difficult fit tolerances had to be produced. The results were convincing: not only was the quality achieved very good, but the new indexable inserts significantly increased tool life by up to 100 percent, even on workpieces that were difficult to manufacture.

The secret behind the very high quality standard achieved in the grinding process for indexable inserts is the EcoDress process. In this process, the grinding wheel is cleaned and stripped after each grinding cycle so that the quality of each individual grinding process remains the same, the grinding wheel does not clog and does not generate cutting pressure. This allows Arno to maintain very tight machining tolerances. The result is an improved surface quality and edge definition of the indexable inserts. In addition, the standard cutting edge rounding contributes to increased tool life and smoother running of the indexable inserts.