Abstract: A ready-to-assemble (RTA) metal cabinet includes an upper cabinet board, a lower cabinet board, a left cabinet board, a right cabinet board, a back board and a cabinet door. The upper cabinet board and the lower cabinet board each include a first connecting structure for connecting the left cabinet board and the right cabinet board; a threaded structure is provided in the first connecting structure; the left cabinet board and the right cabinet board are each provided with an installation hole corresponding to the threaded structure, such that a screw is fastened in the threaded structure after running through the installation hole; a second connecting structure used for connecting the cabinet door is further arranged on the left cabinet board and/or the right cabinet board; and the second connecting structure is provided with a relief groove for yielding a position for installation of the screw.