The curved S-shaped aluminum square pass can also be selected by the welding and grinding of the special-shaped plate processing method. The engraved plate is combined with the welding process, which is generally all-welded, so as to ensure the stability to avoid cracking during processing or transportation. After welding, the front surface needs to be smoothed. Especially if it is required to spray paint or fluorocarbon, it will test the technique of polishing the master. The entire spraying surface, especially the place where the two plates are welded, needs a flat and flat surface. In order to guarantee the quality after spraying.