If anyone can shed some light on this subject. What is the difference in inserts when it comes to machining Aluminum vs Cold roll steel. Why are there two different inserts for the different materials. Basically what I am trying to say is why can't you use an insert that is for aluminum on Steel and vise verse? Any Technical data would be so much help. I just know that there are two different inserts for the job but I don't have much technical info to back it, I need to explain it to management so we can get the right inserts in this place and get the job done right.