A brad point bit, also known as a wood bit, is a tool designed to bore accurately and neatly through wood. Where twist bits might skate around on wood fibre before starting to bore a hole, brad point bits can drill holes with pinpoint accuracy.
This is made possible by the part of the tool that gave it its name: the brad point. The sharp brad digs into the surface of the wood and fixes the bit in place to ensure it bores a hole exactly where you mean it to.
Sharp spurs at the drill bit’s circumference cut cleanly through wood fibres, while horizontal lips shear out material as the drill moves through the workpiece. Effectively, this means the drill cuts the outside of the hole first.
Due to their physical characteristics, these bits are sometimes referred to as lip and spur bits or W-point bits.
Some varieties of brad point bit can be used to drill through materials that are harder than wood. For more information, see: What is a brad point bit used for?