What two thing does it take to make a chip? HEAT and PRESSURE!
Do you really understand the metal cutting process? What is really happening to the material being machined? The metal cutting process is a process of plastic deformation. The material is being plastically deformed and sheared away. This act of plastic deformation requires heat and pressure. The heat is caused by the friction at the shear zone where the tool meets the part. The amount of heat is regulated by the rotational speed of the part in a lathe operation and the rotation of the tool in a machining center. The faster the rotation the more friction and heat the slower the rotation the lesser the heat. The pressure is generated by the feed of the tool into the part. It is important to note the same heat and pressure that is required to plastically deform the material and shear it away is the same heat and pressure that causes tool ware and failure. Therefore it is imperative to find the right balance of heat and pressure for the material being machined to obtain satisfactory tool life.