Drill bits are parts used to cut when someone is using drilling machines. The drill bits are available in different sizes but the metric one is the most popular. The diameter of these drill bits varies depending on your needs. If someone wants to make small holes in a wooden piece, he can buy small size drill bits. When you want to purchase a drilling machine, you should consider the drill bits sizes. Drill bits come in various types that someone can buy depending on where he or she is going to make the holes.