ask This Old House
Q Spade bits, auger bits, and hole saws all make big holes in wood. But what uses is each type best suited for?
—ADAM SZLEMBARSKI, ST. PETERSBURG, FL
A When I need to drill a hole for a door latch, electrical wire, or a water pipe, I’ll use a spade bit, like the ones at left. They’re inexpensive and bore quickly if you apply a fair amount of pressure, but their holes tend to be rough. Maximum hole size: 1½ inches. Auger bits bore more smoothly and pull themselves through wood. They’re great for making the long peg holes in a timber frame, but can tax a cordless drill. They’re not cheap, either. Maximum hole size: 2 inches. Hole saws aren’t bits, but they’re just the thing for cutting wide, shallow holes, like the ones for doorknobs. As with auger bits, hole saws need drills with lots of oomph. Maximum hole size: 8¼ inches.
—TOM SILVA, GENERAL CONTRACTOR
