Install T-nuts easily with this  ace of spade bits

Recessing T-nuts flush with the surface of a shop jig requires at least two bit changes with standard drill bits. So I came up with an easier way. By modifying a ³⁄₄ " spade bit using a grinder and file, I now drill a ¹⁄₄ " hole for a bolt, a ⁵⁄₁₆ " hole for the T-nut's barrel, and a ³⁄₄ " counterbore for the T-nut's head all with one bit.
—Lynn Potter, Green Valley, Ariz.