I've got a job coming up to drill around 300 x 25mm diameter holes in some
powder coated steel electrical enclosures. The metal is 1mm thick, probably
30 - 35 thou. Punching is out, I need to do this using my drill press.

I've done a bunch of holes in the past using a step drill, and then spent
almost as much time again deburring the holes. I'de very much like to avoid
using coolant or Trefolex due to the cleanup involved with the enclosures.

I'd like to drill the holes in one go (ie not pilot then change & drill) any
recommendations as to the best approach or tool that I should use?

thanks