a profiling tool is mounted on a tool slide which can be moved radially towards the electrode roller by means of a feed drive . a feeler slide which carries a feeler can move parallel to the tool slide and is biassed towards the electrode roller . relative movements of the tool slide with respect to the feeler slide , and thus the depth of feed of the profiling tool into the electrode roller , are limited by an adjustable limit stop . the tool slide can be stopped by means of a clamping device as soon as the predetermined depth of feed of the profiling tool is reached . the setting of the profiling tool automatically adapts to the diameter of the electrode roller , which decreases with repeated profiling .