not exactly right. the first is an abrasive disc. that's the right guy for steel, but doesn't work great in aluminum because its very sticky and melty. the third is a metal skill saw blade. I really wouldn't use this with steel at all, but you definitely want to cut aluminum and not grind it. the tool I would normally use for this is a portable bandsaw, with speed control that you would set high for Al and low for steel, probably pretty close to the skill saw.