DURO-key bar chucks and plane spiral chucks (DIN 6350 und DIN 6351) are successfully used wherever extremely high tension forces, high concentric accuracy and reliable continuous repeatability are needed.   The three-jaw DURO key bar chuck is characterised by its very high tension force and accuracy, which is twice a high as prescribed in DIN 6386. The running and run-out accuracy of our three- and four-jawed plane spiral chucks meets DIN 6386, Part 1, Accuracy Class I.   In order to machine large and heavy workpieces at the highest possible cutting capacity, optimum clamping is required using great forces. Röhm plane disks, with a diameter of up to 4500 mm and their indisputable merits have proven themselves here.