Multi-stage cold forging and experimental investigation for the outer race of constant velocity joints

► Traditional warm forging is replaced by multi-stage cold forging for the outer race. ► Two cold forging procedures are reduced in the backward extrusions and the shaping. ► Each split groove knife is developed to pull out those knives from the inner cavity. ► Initial volume of the outer race can be reduced by about 7%. ► Proposed forging process can reduce the total post-processing duration by about 81%.