Clemence said it all. Nice work! 
I like to use a drill press to drill the hole, then mount the tap in the drill press chuck but DO NOT use the power of the drill press to thread the hole! Instead, turn the chuck by hand. This keeps the tap perfectly aligned with the hole just drilled but it also introduces some problems due to the drill press itself. It may be a good idea to get the tap started with the drill press to ensure alignment then release the tap from the drill press jaws and continue with the tap handle by hand.
Thanks for reminding me that I need to do this to the last light I built from scratch…. today probably! (I’ll still forget)