3. 2 Carbide, 1 High Speed Steel. Also snapped a number 1 center drill and a number 3 center drill.
These are our halfhafts for the FSAE car. They're hardened 4130 Steel. I had to drill a 1/16" hole through them. It took some ingenuity. If you're interested how I did it and why I did it the way I did, you can ask and get a full explanation, but it was a major PITA. Time for Mac N Cheese, beer, and TV.