Many do-it-yourself projects involve drilling a hole. To properly drill a hole--no matter what material you're drilling--you must use the right size drill bit. Following these guidelines will help you decide what size drill bit to use for your task.
Understand what a drill bit is and what it is used for. The bit is the detachable part of your drill that cuts the material's surface and fits into the drill's "chuck."
Use a standard twist bit if you are boring into wood, plastic and/or some metal. Primarily for drilling small holes, twist bits come in sizes 0.8 to 12 mm.
Select a masonry bit if you need to drill through brick, stone or concrete. Bit sizes range from 4 to 16 mm. Long bits measuring 300 to 400 mm are available for use on masonry walls.
Consider using a bullet pilot point drill bit for a cleaner hole with minimal breakthrough damage to the back of the material. Bit sizes range from 1.5 to 13 mm.
Choose an adjustable wood bit if you need to drill multi-diameter holes. These bits adjust to a diameter that measures between three-quarters and three inches.
Pick a hole saw drill bit that is ½ to 6 inches in diameter to make large diameter holes in wood and light metal.
Elect to use a spade drill bit with a diameter between ¼ to 1 1/2 inches if you are making large holes in wood.
The size of the drill bit depends on the size of the area to be cut out. Follow drill manufacturers' recommendations when selecting a drill bit.