In the production process of aluminum tubes, there are two production processes: seamless and seamed. In the process of extruding the slotted pipe, the blank is extruded through 3~4 holes in the die, and a welding line is naturally formed at the joint. After anodic oxidation, obvious weld lines will appear at the weld lines. If the product requires high oxidation and weld marks, it is recommended to use seamless aluminum tubes, because seamless aluminum tubes are extruded as a whole in the process of backlog, and there are no weld marks.