Hole Saw
Affiliate link — we may earn a commissionA hole saw is a cylindrical saw blade with teeth on the rim, mounted on a mandrel (arbor) that fits in a drill chuck. The center pilot bit keeps the saw tracking straight while the teeth cut the circle. Sizes range from 3/4-inch to 6 inches. They cut large holes in wood, plastic, drywall, and thin metal. Cutting depth is limited by the cup depth, usually about 1-1/2 inches. For thicker material, you cut from both sides and meet in the middle. Bi-metal hole saws handle wood and metal. Carbide-tipped versions last longer on abrasive materials like cement board and fiberglass.
Why It Matters
Door locksets, recessed lights, plumbing penetrations, and junction boxes all need holes bigger than a standard drill bit can make. A hole saw set covering 3/4-inch to 2-1/2-inch handles the most common sizes. Run them slow (300 to 800 RPM) and let the teeth do the cutting.