It's Metal Removal Rate

​Look at the data above. Which tool would you pick as the most productive AND the most economical?

​Here's the rest of the data. A lot emphasis is on Inches Per Minute. What is really most important is how quickly you are filling up those chip barrels. Its metal removal rate (MRR) expressed in cubic inches (or meters) per minute and how much it costs to get there.

Of course, finishing is a different animal.