I have a mill that I've owned for over 25 years. I work on whatever with it. Wood, metal, plastic, I grind sometimes. Just clean and oil your machinery regularly and you'll be far ahead of what most production equipment is made to deal with. Tools are made to be used. Anyone that tries to tell you anything different is a fool. They'd all have heart attacks if I ever took them to E P Heller's shop. He works all in carbide. Someone's gotta. Talk about abrasive grit.