AbstractThe EFDA Close Support Unit (CSU) has initiated a technological development task to manufacture three full scale models of the austenitic steel cases of the ITER Toroidal Field (TF) coils. The main goals are to verify the feasibility of such a thick construction, assess the achievable material properties, and develop the manufacturing processes and quality control procedures. A first model (called Model 1), reproducing the geometry of the inner curved region of the TF coil, has been manufactured with thick forgings. A second model (Model 2), representing the geometry of one outer intercoil structure, has been produced by casting. A third model of the inner straight leg is being manufactured. The work has included a large campaign of development and qualification of welding processes and inspection procedures for thick case sections. Numerical models for the prediction of the geometrical deformations and residual stresses due to the welding have been developed. The goal of this task is the assessment of the manufacturing and quality procedures for the production of the ITER TF coil cases.