Drill bits are cutting tools that are made to fit into a rotating drill. A drill, fitted with a drill bit, is used to cut cylindrical holes of many different sizes in many different materials. The terms drill and drill bit can be confusing as sometimes they are used to describe both the cutter holder (drill) and cutter (drill bit) itself.

Drill bits are available in a wide range of sizes and types. A steel drill bit is usually less expensive than a carbide-tipped drill bit. The best idea when buying drill bits is to find the kind that offers the quality and features most needed for the job.

Drill bits are often sold in sets along with a drill. A set for the home may include general purpose bits for use mainly on wood. The three main types of wood drill bits are flat, dowel and auger. A flat drill bit is sharp with either a point or a screw in the middle to get through wood. A dowel drill bit may also be called a lip and spur bit.

A dowel drill bit features cutting spurs and a sharp middle point. It's ideal for drilling holes in wooden dowels because it is designed to leave a smooth result. An auger drill bit has a corkscrew or twisted shape with a broad cutting edge and it can also produce smooth and accurate cuts on wood. Twisted drill bits are the type most commonly available. A twisted or twist drill bit can make small holes in wood as well as metal.

A step drill bit is used for drilling holes in metal such as aluminum, brass and copper. Glass drill bits are made for cutting holes in either glass or tiles. Installer drill bits are used to install television cable and phone wires. An installer drill bit features a hole to allow the electrical wire to go through. Although most people prefer using electric drills today, hand or manual drills are often still available.