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.

Straight flutes withstand the heavy pressure needed to penetrate hardened steel. These bits cut more aggressively and resist stress better than spiral-flute bits. A lower-priced alternative to solid carbide, they stay sharp when drilling abrasive material but won’t last as long.

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.

When one end wears out, switch to the opposite end for two times the life of a standard high-speed steel end mill. Made of high-speed steel, these end mills are for general purpose milling in most material, such as aluminum, brass, bronze, iron, and steel. Their square ends make them good for milling square slots, pockets, and edges. All are center cutting, allowing plunge cuts into a surface.

End mills with fewer flutes provide better chip clearance for high-volume, high-speed plunge, slotting, and roughing cuts; end mills with more flutes provide a finer finish and operate with less vibration when run at high speeds.

When one end wears out, switch to the opposite end for two times the life of a standard cobalt steel end mill. With better heat and wear resistance than high-speed steel, these cobalt steel end mills can run at higher speeds and provide better performance on hard material, such as iron, hardened steel, titanium, and tool steel. Their square ends make them good for milling square slots, pockets, and edges. All are center cutting, allowing plunge cuts into a surface.