Tough and wear resistant, cobalt steel bits last at least twice as long as high-speed steel. They can also run up to 25% faster at higher temperatures without being damaged on hard materials, such as nickel.

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.

Performance similar to solid carbide but at a lower price point. Like carbide bits, these are stronger than cobalt and high-speed steel and maintain their sharp edges when drilling abrasive material. However, when drilling tough metals like iron and hardened steel, upgrade to carbide for longer life.

With flutes that lift chips out of the hole, you don't have to stop drilling to clear these bits manually. They improve coolant flow to dissipate heat and prevent clogs that can damage the bit and ruin the hole. High-speed steel is good for general purpose drilling in most metals.

The flutes spiral in the opposite direction of other bits and stay sharp longer than high-speed steel. They’re primarily used to remove stripped screws. Choose a bit that’s slightly smaller than the diameter of the screw’s head. Set your power tool to rotate in reverse. Slowly drill in the center of the screw head, maintaining constant pressure. As the bit penetrates, it will catch onto the screw and reverse it out of the hole. If the screw is badly stripped, you might need to punch a starter hole. Also known as reverse-flute bits.