“GROB” forming

Precise

For even greater tooth depths, we use the “GROB” cold forming process (named after the Swiss machine tool manufacturer Ernst Grob AG), which reshapes the workpiece using rotating rollers.

1. Setting the process in motion:

The preform (for example, a deep-drawn bowl) is pushed tight onto the toothed tool mandrel and clamped with a pressure plate. On either side of the mandrel are pairs of rotating rollers orbiting on a rotating arm. Both the main spindle and the arms with the pairs of rollers begin to turn.

2. “GROB” forming:

At the closest point of its circular path, each rotating roller applies pressure to the preform, causing the material to flow. The preform is plastically deformed axially along the geometry of the forming mandrel until the teeth are formed to their final depth.