Ziehstufen

Ziehstufen is a term used in metal forming to describe the successive steps in the drawing process, in which a workpiece such as a wire or tube is reduced in cross-section by passing it through a series of dies. Each Ziehstufe corresponds to a single drawing operation with a specific die size, and the sequence of stages is designed to achieve the desired final diameter and mechanical properties.

The design of Ziehstufen takes into account the allowable draw ratio per stage, the ductility of the material, and the effects of friction and lubrication between the workpiece and the dies. The overall draw ratio is the product of the stage draw ratios, and the final dimensions result from completing all planned stages. In practice, intermediate annealing may be performed between stages to relieve work hardening and restore ductility, especially for metals that harden quickly.

Applications and implications: Ziehstufen are common in the production of ductile metals such as copper, aluminum, and steel wires, as well as in tube drawing. A multi-stage approach reduces the peak drawing force, lowers the risk of fracture, improves surface finish, and enables precise control of geometry and material properties. The number of stages and the choice of die sizes depend on material properties, target dimensions, and required mechanical characteristics. While staged drawing offers advantages in control and final quality, it can involve higher equipment costs and longer production times.

In German-speaking engineering literature, Ziehstufen specifically refer to these discrete passes in a drawing process; in English, the concept is frequently described as drawing passes or draw stages.