For cutting steel box tubing, square tube, angle iron, pipe, and metal roofing, the Xiphos™ 7-1/4″ steel circular saw blade is the best option. Xiphos™ is made for slicing through mild steel without creating burrs or generating heat.
The Xiphos is designed to cut a wide variety of wood, metals, and plastics with out the need of changing blades. With that being said it is not designed to excel in any specific material. Ex. Xiphos will cut ply wood but may not be the best option.