A manufacturer of automotive components uses different grinding machines in order to grind parts for steering systems. Because of the high quality requirements the surface of the parts has to be absolutely smooth and must not show any dents or scratches. In order to guarantee the required quality the coolant in the grinding machines has to be as clean as possible. Particles, which are flushed with the coolant between grinding disc and work piece, may cause scratches or rills. In order to keep the coolant as clean as possible, the company used different filter elements with different pore size. Although the coolant was more or less clean, customer complained from time to time the surface quality of the parts. The company was looking for a technology in order to remove more or less all particles down to 1 µm at reasonable cost. The maintenance manager was especially interested in a system, that does not cause high cost for consumables and that does not produce lots of waste.

The production manager and maintenance manager decided to install a Friess magnetic filter type FMF 420/6. After installation of the magnetic filter particle analysis of the coolant was made. The analysis showed, that the coolant that was sprayed through nozzles onto the grinding disc and the work piece, was free of particles bigger than 1 µm. The installation of the magnetic filter FMF 420/6 was essential for the improvement of the cleanliness of the coolant. Because of the extreme high cleanliness of the coolant the surface quality of the parts was drastically improved. Since the magnetic filter is in operation no parts were rejected because of scratches or dents in the surface. Because of the good results a second system was equipped with a magnetic filter FMF 420/6.

Magnetic filter rods with fine particles collected from coolant in grinding machine