Just a hint.
If you need to drill several holes with different diameters in your piece of work: DRILL THE SMALLEST DIAMETER FIRST!!!.
When you, by mistake, should drill a hole on a wrong spot, you can always drill it wider afterwards.
If you don't, and work the otherway around, I found out one can get in serious trouble.
Also drilling (and tapping) the most difficult holes, mostly the small diameters, first, can save you a lot of time in case you have to start all over again because of a broken non removeable drill.
Happy drilling.
Frits, who is busy with his bogies, but need more time than he suspected.