Pilot drill diameter(s) — This enables and sets a list of drill sizes used to drill pilot holes. Enter a list of drill diameters to use for pilot drilling, with a comma between each.
For example, enter 0.5, 1, 1.5 in inches, to pilot drill with the half inch drill for final hole sizes up to an inch. A hole bigger than 1.5 inches is pilot drilled with all three of the specified drills before being drilled to size.