The hardest and most wear-resistant bits for sheet metal and thin-wall tubing. They have short flutes that make shallow cuts without snagging and deforming the material. Carbide stays sharp at high temperatures and faster speeds than high-speed steel. It can be brittle, however, so these bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.

Make rough holes in wood for jobs such as running wire and pipe through framing studs and sheets. These bits have two sharp edges for faster cuts than fluted bits and won't cause the surface of the material to splinter. A centering point keeps them stable while drilling soft and hard woods such as pine, plywood, and oak. Also known as spade bits.

Bore a variety of hole sizes with one bit—just slide the blade to the desired diameter and then tighten the screw. These have two sharp edges for faster cuts than fluted bits and won't cause the surface of the material to splinter. A centering point keeps them stable while drilling soft and hard woods such as pine, plywood, and oak. Like standard flat-blade bits, these drill rough holes but should be used in a drill press rather than a hand-held tool. Also known as spade bits.