Square
The high cutting speed of CO2 lasers is what makes them stand out. Their main application area is the medium-to-high range of material thicknesses. The laser beam cuts with high precision and is free from burrs. This allows the parts to be processed further without needing to be reworked.
The very nature of a tube prevents the need for a machine with a very high-powered laser. Whereas flat sheet laser cutting machines now are available with laser generators as powerful as 12 kW, tube laser cutting machines usually only require a maximum of 5 kW of power. With a tube, you always have to think about the opposite side of the tube you are cutting. A more powerful laser simply would blow through the other side of the tube during cutting. (Of course, if you are processing a beam or a channel on the tube laser you don’t have to worry about another side.)