With flutes that spiral in the opposite direction of other bits, these are 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. High-speed steel is the versatile choice for drilling most metals.

All of the bits in these sets have the same shank diameter, so you can quickly change sizes without swapping out the collet on your tool. Because of their small size, they are often used for drilling holes in circuit boards. Carbide bits are the the hardest and most wear resistant. They stay sharp at high temperatures and faster speeds for the best performance on hard and difficult-to-machine materials. Carbide can be brittle, however, so bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.