The machining of metal surfaces has always been an important manufacturing function within the Hunger Group. In addition to the design and manufacture of efficient honing machines, the research department also gave consideration to the development of effective abrasive agents and cutting tools. In 1979, Hunger Schleifmittel GmbH was formed as an independent company. It now supplies cutting tools and honing stones not only to the Hunger group but also to third party customers around the world. The production range consists of plastic coated honing stones and diamond honing tools for micro-finishing metal surfaces. New products have undergone intensive testing and inspection by the Hunger Group under actual working conditions before being introduced to the market. This ensures a top quality product and guarantees customer satisfaction.
The final finish is of utmost importance because the quality and service life of hydraulic cylinders heavily relies on the surface finish of its individual components. If compromises are made, then this will result in reduced efficiency as well as shorter working life. The reputation of Hunger Schleifmittel GmbH is excellent. High stock removal rates, dimensional accuracy and constant quality are distinctive features. Diamond tools are used not only in the hydraulics industry but also in machine tooling and automotive manufacturing. Hunger products are used to finish engine blocks, connecting rods, brake cylinders and valves. In addition, Hunger develops and produces complete tool systems to satisfy the special requirements of the automotive industry.
The more frequent use of ceramic coated piston rods has given the engineers of Hunger Schleifmittel GmbH a new challenge. For the finishing of large diameters and long lengths of ceramic coated piston rods, a special diamond honing bar has been developed to meet the requirements of removal capacity and surface finish by utilizing the many years of experience and know-how in bonding and grain assembly. By using a soft bonding and grain assembly, high removal rates at low contact pressure can be achieved. Surface finishes of 0.1 µm Ra are possible even at high rates of removal.
Many years of research and development by Hunger have led to a new process - pressure compaction. A completely new path is paved with this process. The spherical tool is subject to a large force which simultaneously transforms and hardens the surface of the workpiece. Resulting benefits include: reduction of wear on bearing surfaces and guides, reduction of stress concentration at change of section (crankshafts), increase in contact area of bearing and piston surfaces, reduced running-in wear in compressor and engines, decrease in friction between running surfaces, enhanced decorative finish, and so on.