NC Drill File: The NC Drill file defines hole locations and tool numbers (X&Y coordinates).
All holes are plated through: there will be solder in the hole barrel.
 •Preferred format is 2.4 non-metric.
 •Drill file must be ASCII text viewable.
 •PLEASE CHECK THE DRILL FILE IS NOT A DRILL IMAGE OR FAB DRAWING!
 •Please view your NC drill file in notepad or word pad to verify it is ASCII text.
Drill file should not contain “G01, G54”, or "D" (this indicates a Gerber format) code references when opened in Notepad.
There must be "T" codes separating tool sizes (T1, T2, T3).