How to Drill Glass without Glass Damage

What You'll Need
Drill bits
Rubber pad/cushion material
Glass drill bit set
Variable speed drill
Cutting oil or water spray

Learning how to drill glass without breaking it is very simple if the proper tools are at hand. It is important to have the right kind of drill bit for the glass.  If you do not use the right drill, then you can be sure that the glass will crack or completely break. If possible it is best to not drill through glass though sometimes it is necessary.

Step 1 – The Glass

Ensure that the glass needed is the correct thickness and size. Safety glass and tempered glass should not be used. Very special equipment is needed for safety and tempered glass. This equipment is not available at the local hardware store.

Step 2 – Glass Bits

In order to drill though the glass, special glass drill bits are needed. These types of bits will be made of tungsten carbide and will have a point that is shaped like a spade. The tungsten carbide can stand up to the amount of friction that is created when drilling glass. It is also possible to use diamond bits but, 2 diamond bits will be needed for drilling where only 1 tungsten carbide bit is needed.

Step 3 – Measure

Once the glass is cut, measure where the holes will need to be. Do not drill holes within 3/4 of an inch form any edge. It is best to stay as far from the edges and corners as possible.

Step 4 – Support

For drilling the glass will need to be supported. Place it on a surface that is very flat. If possible, have a type of very firm cushion material or a rubber pad underneath the glass. It is vital that the glass is properly supported and flat.

Step 5 – Drill

Use a variable speed drill for drilling. Start with a small drill bit and then place the bit so that it is in the center of the hole. Start drilling and use constant pressure. It is best to drill in a slow and steady manner.

Step 6 – Reverse

Before the drill goes completely through stop drilling. Many times if the drill bit goes completely through it will chip the back side of the glass. Flip over the glass and drill thought the backside to complete the hole. Drilling through the back of the glass produces a much cleaner hole.

Step 7 – Get Bigger

Start small and then start using increasingly larger drill bits until the desired hole size is achieved. Make sure that each new drill bit completely creates a larger hole before going up another size. Going from a small drill bit to a very large drill bit will damage the glass. As the bits get larger a lower drill pressure is needed. With too much pressure the bits will not cut through the glass.

Important Tips

Using a sequence of increasingly larger bits is very important because of the different pressure needed. Adding a little bit of cutting oil can help with the drilling process. For glass, water spray or even a water bath is the best.