Manufacturing of pedestal supporting error field correction coil in JT-60SA

•Pedestals must withstand electromagnetic force and also allow relative displacement.•Pedestal structure was designed with finite element method and verified with mock-up.•Depth and diameter of plug welding were adjusted to minimize welding deformation.•Load test using mock-up showed enough strength (>10 times the expected cycles).•Manufacturing of 3 types of pedestals (432 in total) has successfully completed.