many years ago I worked for a company , manufacturing CARBON BRUSHES for electric motors, one of the process steps was to drill the holes for the copper braid .

We used standard HSS drills and had to resharpen every 6-8 Brushes, the foreman brought in several drill bits with a GOLD coating which believe was TiN , we trialled these and found that we could get an extra 4 holes before the edges went west and we needed to resharpen, then they were no better than HSS.

These cost twice what HSS bits cost at the time but in the long run were no better.

Jeff