An NC Drill (or Gerber) file for each drill depth (through holes, each blind hole depth, each buried hole span, etc).

NC Drill files should preferably be in XNC format, alternatively in Excellon format.

NC Drill files should include tool diameters. If not, then a tool list must be supplied for each NC Drill file.

Plated and unplated through holes should preferably be in the same file, but may be in separate files.

NC Drill files should preferably be in 3.3 METRIC format.