Start-ups in the machining services sector have to assert themselves against tough competition. They cannot afford to waste money on procurement. This is also the case for Bonertz Technik from Föhren, which was founded in 2014 and has now made the leap from a pure service provider to a manufacturer of innovative clamping devices for use in machine tools. When purchasing cutting tools, the company focuses primarily on performance, process reliability and good support. "When we founded the company in 2014, we only had one CNC machine and initially worked purely as a machining service provider," recalls Managing Director Robert Bonertz. The company gradually specialized more and more in demanding tasks. Bonertz Technik deals with materials that are difficult to machine - special alloys, high-strength steels up to 1,100 ^N/mm2 or super-hard materials with up to 60 HRC. Components that require complex clamping are also a specialty of Bonertz Technik. Examples of this are filigree structures that have to be machined out of solid material with a high proportion of machining. Satisfied customers enable the company to grow rapidly. Today there are four modern, high-precision 3- and 5-axis milling centers in the production area. The necessary infrastructure in areas such as work preparation, CAD/CAM programming and quality assurance is also in place.

Development of advanced clamping technology

"With many machining tasks, we were always annoyed by the inadequacies of the available clamping technology for clamping the components," recalls Managing Director Patrick Vilfan. This was particularly evident when the components to be machined had to be re-clamped due to frequent product changes. Due to the cumbersome handling, this took far too much time, which was detrimental to productivity. In addition, some of the clamping devices were very bulky and created interfering contours that hindered the machining process. Another disadvantage of the conventional clamping devices was their height, which limited the available travel in the Z direction.

For this reason, those responsible at Bonertz Technik decided to produce better clamping devices. And not just for their own use, but also for marketing. Over time, various versions of 5-axis clamps and an innovative machine table were developed as an alternative to costly zero-point clamping systems.

Practicality in the foreground

"Practical considerations were at the forefront of our developments," explains Vilfan. In addition to high clamping force, an important feature was extensive modularity in the design. Depending on the design length, the base rails are equipped with a variety of interfaces to the machine table. The clamping range can be easily extended from 10 to 1,335 mm using intermediate pieces without any loss of clamping force. The maximum clamping force is 50 kN. The jaws, which are available in a wide range of variants, can be replaced without tools in just a few seconds. In practical use, the systems have resulted in set-up time savings of up to 90 percent. The developers paid particular attention to avoiding interfering contours. This is why the clamps are also available in several height variants between 130 and 210 mm.

"The contact with Bonertz Technik came about by chance a few years ago because they were a contract manufacturer machining components for one of our subsidiaries," recalls Klaus-Dieter Leick, application engineer at Mapal. He came into contact with Bonertz when they were having problems machining high-strength tool steels with trochoidal milling cutters from a competitor.