CNC Rebar Cage Rolling Welding Machine Automates the production of reinforcement cages for bridge piers, pile foundations and viaducts. Main bars are loaded once; stirrups are fed, positioned and welded continuously while the cage rotates on the disc — output is measured in cages per shift rather than per welder. Why It Pays Off Cage tying is the most labour-intensive step in pier and pile production. The figures below are running-cost items a site manager can verify against