Mechanical Engineering - Workshop Technology - Discussion

The correct answer is annealing is needed between stages.

Tandem drawing is a process used to reduce the diameter of wires and tubes in multiple stages. This is necessary because:

Work hardening: Drawing can cause the metal to become harder and more brittle, making it difficult to further reduce its diameter.

Annealing: To prevent work hardening and improve the ductility of the metal, annealing is typically performed between drawing stages. Annealing is a process of heating the metal to a high temperature and then cooling it slowly, which softens the metal and restores its ductility.

While accuracy in dimensions and surface finish can improve with each drawing stage, these are not the primary reasons for tandem drawing. The main reason is to prevent work hardening and ensure that the metal can be drawn to the desired diameter.