How To Drill Acrylic Sheet Without Cracking?

Why drill acrylic?

We are going to think about some reasons why you might want holes drilled into your plastic. Primarily, our customers require holes drilled in their acrylic to mount the plastic to a wall. 

This is because acrylic is an ideal material to use as a glass alternative throughout the home. It is half the weight of glass and shatterproof, making it both safer and more durable. For instance, you could use two clear sheets of acrylic as a picture frame for family photos or artwork. 

Another key use of acrylic is as a mirror. Our customers have used plastic mirrors in a wide range of scenarios, including in bathrooms, kitchens, gardens, and to make their very own mirrored wardrobes and furniture. While you can glue acrylic mirrors in place, they can also be screwed into the wall. 

Why does it crack while drilling acrylic sheet?

Acrylic is an alternative to the glass material. It can serve many purposes where a light weighted, and weather-resistant material is required. You can reshape the plexiglass effortlessly by applying heat to it.

However, due to its brittleness, it has greater exposure to scratches and is at high risk of cracking. It happens because when drilling, it tends to heat up quickly and gets fractured in no time. The extreme force that comes while drilling increases the friction, and thus the plexiglass expands due to the heat.

So if you are going to drill into plexiglass, make sure you keep a calm hand on the drill to avoid the melting of the glass.

Select the right tool

Regular drill bits for metal and wood will break the edges and shatter the plexiglass during drilling, but there are special drill bits developed specifically for plexiglass, and you should use one of them instead of the standard drill bits.

Types of drill bits to avoid Cracking in Acrylic

  • Standard Twist Drill Bits
  • Plastic Drill Bits
  • Step Drill Bits
  • Cone Drill Bit
  • Spiral Drill Bits
  • Spiral Drill Bits

Drilling guidelines for Drilling into Acrylic

The drill bit used for drilling plastic materials should be specially designed. The top cone Angle was 60 to 90 degrees. The posterior Angle of the blade is 12 degrees to 18 degrees.

In the process of processing, the compressed air is blown into the chip to prevent overheating caused by the blockage.

The drilling processing speed of thermoplastic materials is determined according to the type of material, the size, and the depth of the hole. With the increase of borehole diameter, the velocity decreases. The hardness of the material increases, and the speed increases. Follow the table.

Hole size (mm)234568101214
Drill bit diameter (mm))
Speed (RPM)500050003000280025002000180010001000

Make the drill

Begin by securing your acrylic on a flat surface. Use clamps or weights to keep it in place and prevent the material from warping or spinning during the drilling process.

To drill a plexiglass, begin to pierce the marked spots slowly. Don’t push too hard; you can aim at a speed of 3.5 inches per minute.

Begin by making a pilot hole of about half the diameter of the intended hole and gradually increase the hole by moving to the next size of bit drill until you get to the actual one.

For example, to drill a 1/2-inch hole, you can make a pilot hole by beginning with a 1/4-bit drill and then moving to a 1/2-bit drill.

While you are drilling through the plexiglass sheet, the friction would produce intense heat and the bits would cause lots of plastic shavings around the hole, especially if the sheet is thick. So you can often take a break to clean the plastic shavings from the hole so you can have a more unobstructed view of the job.

Use some spray lubricant to make the drill bit wet, not only to prevent the heat from damaging it but also to keep the acrylic from cracking, chipping and even melting.

After you are done with your drill, allow it to cool and clean the surface of the plexiglass, and you would have a nice result.

Tips While Drilling into Acrylic

  • Do not remove the masking film from the acrylic sheet.
  • use a drill bit that is the correct size and has the correct taper to avoid cracking your Plexiglass.
  • Keep the Drill Bit Parallel to the Plexiglass
  • Drill at a Slow Speed
  • Apply Oil or dishwashing liquid to the Drill Bit, WD-40 is the ideal option.
  • Safety first! -wear safety gloves while you are drilling

How to repair Acrylic if it cracks?

Already got a crack in your acrylic sheet? Don’t worry, as it can get fixed easily with solvent cement. If you didn’t know, solvent cement is a solvent-type bonding agent that can weld acrylic by softening it.

So to repair the plexiglass when it cracks, use a very considerable amount of the solvent over the crack line and let it stay there for a few hours. It is essential to leave it for that much time to build up the required strength. You can also use a plexiglass adhesive for this purpose.


When you’re drilling through Plexiglass, you must pay attention. Though it’s not as strong as glass, Plexiglass can still crack or shatter if the pressure is too high or if you are drilling it too quickly. To ensure that your Plexiglass is protected, always ensure it’s anchored on something stable.

Still confused about how to drill plexiglass without cracking? Try KUSLA Acrylic drilling service!