How to Choose the Right Drill Bits?

The type of drill bit you need to use depends on what kind of material you are drilling.

Metal Drill Bits
These bits are for drilling different kinds of metal, but they can also be used to drill wood. High-speed steel (HSS) is the most common material used in metal drill bits. For long-lasting use and for harder materials, buy tungsten carbide or cobalt drill bits.

Glass, Tile Drill Bits
These drill bits look like a small spear. They have a steel shaft with a carbide tip. When drilling onto glass and tiles, use a low speed on your the drill and disengage the hammer impact mode (if your drill is a hammer drill). Sizes for glass and tile drill bits are limited.

Masonry and Concrete Drill Bits
Like glass bits, these have a steel shaft with a carbide spear joint brazed into them. The tips are much thicker and are made of impact-resistant carbide. The flutes and shafts are also stronger, to withstand tougher jobs.s

Wood Drill Bits
The tip of wood drill bits have one central point. With a high cutting capacity, these bits can be used on all types of hard and softwood, plywood and veneer.

Flat Wood Bits
Flat-sided drill bits range in sizes from ¼” to 1-1/2”. They have a long central point to position the bits better. They are economical, do the cutting job quickly and are easily re-sharpened. It is best to set your electric drill to a slow speed when using them, as they can burn after lengthy use; be especially careful when drilling hardwoods. Stop the drill from time to time and allow the drill bit to cool down.

Expandable Bits
These drill bits have a central screw point to help pull them through the wood but with a flat cutter and a single spur. They are ideal for larger holes, but they must be kept sharp in order to work effectively. 

Hole Saws
One of the common uses of hole saws is to create holes in doors for locks and security peepholes. There are two types of hole saws: one uses spring steel cutters, which lock into an arbor. The other has a welded steel cup design, which is threaded onto an arbor.