In both can-making welding and overlay welding, invisible residual stress is always generated during welding. We have a total of three heating furnaces, one large and two small, which are necessary for heat treatment (annealing) to remove this stress, and we have timely in the process to reliably remove this invisible residual stress. Annealing is done. By doing so, the strength of the product will increase, and we will provide products that can withstand use in actual harsh environments. Even if it’s hard to see, we never cut corners in performing quality construction.