Spade bits can bore large holes fairly quickly. Careful though, the holes shouldn't overlap as it can cause the bit to catch and twist your arm. If you must drill overlapping holes it is safer to use a Forstner bit.

Irwin Industrial Tools 341008 8-Piece Speebor Blue Groove Pro Set Case . For fast, rough or clean and exact holes, Irwin's extensive line of woodboring drill bits provide the user with the best available tools for each application in achieving their wood drilling needs.

from $23.97