Deep Hole Drilling for Castings: What to Watch For
Castings are different from wrought material. The grain structure is not uniform, there can be porosity, and the surface has a tough scale layer. I have drilled plenty of cast iron and steel castings over the years, and I have learned that treating them like wrought bar stock is a fast way to break a drill. The main differences from wrought material are the entry surface and the internal consistency. Here is what I have learned from drilling thousands of holes in castings. ...