Kostwein Maschinenbau sees itself as a strategic partner for outsourcing for leading machine manufacturers of textile machines, packaging machines, printing machines, machines for the pharmaceutical industry and machine tools. However, the customer base also includes aircraft manufacturers and wind turbine manufacturers.

The focus of production is on the complete manufacture of machines and modules in series of 1 to 300 units per year. Complete welded constructions are manufactured in-house, but further processing and assembly also form an integral part of the partnerships. Milling operations are possible up to a size of 10 m x 3 m, and turned parts can be machined up to a diameter of 2.80 m.

True to the motto "The customers' core competence lies in product innovation, Kostwein's core competence is process innovation to manufacture these products optimally", the Austrian supplier for mechanical engineering has set itself the goal of continuously reviewing and optimizing its manufacturing processes.

In 2014, for example, a workpiece for the packaging industry was subjected to a series of machining tests with products from various precision tool manufacturers. The workpiece was an extremely unstable welded construction that was produced in large quantities. This required particularly light-cutting tools as well as optimization of the entire machining process in order to increase efficiency.

The Ingersoll tool specialists selected a GoldTrio corner cutterhead with a diameter of 63 for this machining process. The tool series is characterized by good plungability and a particularly soft cut and is also more economical than the high-positive variants with a double-edged indexable insert thanks to three usable cutting edges.

From test case to standard

The corner milling cutters were used as the last variant in the test series and immediately positioned themselves as the top milling cutters: In addition to the smooth and low-vibration cutting behavior, the tool life and process reliability stood out positively.

After the corner cutter was also able to prove itself on other workpieces, it became the standard corner cutterhead throughout the Kostwein Group. For Jörg Schrattel, Head of Tool Management at Kostwein, it was clear that this joint success in process optimization would not remain an isolated case. "Ingersoll is on site with us from the initial idea through to testing and production," he says, praising in particular the commitment of the responsible Ingersoll consultant Thomas Schwarzenegger.

While analyzing the machining processes, Kostwein's production management came across another workpiece that required optimization. It was a component for the packaging industry whose surface quality made the experts dissatisfied. At the beginning of 2016, Thomas Schwarzenegger was approached by Jörg Schrattel about this problem and asked for a tool proposal.

The tool specialists chose a side milling cutter from the GoldSlot series with a cutting width of 10 mm and a diameter of 125 mm. The heart of this side milling cutter series is the so-called bridge plate. It allows a stable clamping situation and a maximum screw-in depth of the clamping screw. The result is a high level of stability, even with one-sided cutting loads.

Another advantage of this series is the creation of a flat groove base without a roof shape. This is achieved by a special grinding on the indexable insert, which compensates for the angular error caused by the lateral clearance of the indexable insert.

Pre-milling of large holes

The economical and flexible machining of large bores is another task that Schwarzenegger was approached about by Kostwein production planning. It was quickly agreed that the pre-machining of the bores should be carried out with a milling tool using the circular milling process. By programming the bore diameters, this process is so flexible that the number of tool diameters required is low and therefore fewer chain positions are occupied. Points that support the desired flexibility.