Steel
Be aware that there is no perfect tub. They may have bows. You may find weld seams on both the outside and the inside of the tube. When there are inconsistencies between product runs, it can be a challenge to process the material efficiently and consistently.
With a laser tube-cutting machine, there are no standard towers. Bundle loads are the most efficient method for handling tubes. These loaders feed one tube per bundle into the tube cutter via a singularizing mechanism. This feeding method is not compatible with open profiles such as angles or channels. Because they interlock within a bundle, and don't allow for easy release, this type of feeding doesn't work. Step loaders are employed for open profiles. These machines sequence one section at a time and maintain the correct orientation.