Drill Bit Types

Twist Bit

The twist bit is the most readily available and thus most often used for drilling small holes in wood or metal.

For wood applications, it is highly recommended to use a piece of waste for backing to avoid blow out.

(I) The left most bit is a standard twist bit (for metal or wood)

(II) The middle bit is a brad point bit (wood only) allows for a accurate starting point

(III) The right most bit is a masonary bit (for cutting concrete or ceramics)

Tips of twist bits are different for various uses:

Spade Bit

The spade bit is an inexpensive bit used for drilling larger holes in wood.

The centre point allows for accurate starting and it will remove material quickly.

However it will not produce a very clean hole

Forstner Bit

The Forstner bit is used for drilling larger holes in wood.

It will produce the cleanest hole of any drill bit and results in a flat counterbored hole. This can be helpful to hide screw heads with a dowel plug.

There are different types of forstner bits classified on how the edges are cut.

Counter Sink Bit

The countersink bit makes a pocket into for the head of a screw to sit in.

This bit allows a screw to be set flush with the surface of a piece of stock or slightly below

Hole Saw

These saws are for making very rough holes and you must cut all the way through the stock to make the hole (you can not simply stop part way through like a forstner bit)

Depending on the type of teeth, hole saws can be used for cutting wood or metal (top picture)

For cutting ceramics (diamond dust "teeth")

Combination Countersink Bit

This bit will drill a hole in sone step that allows a screw to be installed so that it is set below the surface of the wood. Shown below is a picture of the hole this type of bit will drill.

Often the bit used can be changed to use a spindle or brad point.

The set screw on the side is loosened, and the drill bit can slide out. These are used most often when building on site.