[sanddrag]

We were going to see if we could machine the hex, and the machinist would be happier (and could use smaller tools) if they were made from aluminum, but since a knowledgable person (Travis) is concerned, we'll just do steel. I just wanted to know if we could get away with aluminum, but I share your concern for things like wear on the hex and on the edges of the dog "fingers." If we take shallow cuts and slow feeds, we should be able to do the hex in steel. We'll just have to buy the machinist lunch.