7 minute read -
How to Cut Perspex and Acrylic Sheet: The Right Saw, Blade and Settings
The best way to cut Perspex is with a jigsaw fitted with a fine-toothed blade for plastics or non-ferrous metal, set to a medium speed with the pendulum action switched off. For long straight cuts in thicker sheets, a circular saw with a fine tungsten carbide-tipped (TCT) blade works better.
Leave the protective film on the sheet, clamp it firmly and cut at a steady pace, so the acrylic sheet does not melt or crack. Below you will find how to choose your saw and blade, which settings to use and how to finish the edge so it looks clean and clear.
What will you learn in this article?
- Why is Perspex tricky to cut?
- Cast or extruded acrylic: does it matter?
- Which saw is best for Perspex?
- Which blade should you use for Perspex?
- How should you set up your jigsaw for Perspex?
- How to cut Perspex in 6 steps
- How do you stop Perspex melting or cracking?
- Can you cut Perspex without a saw?
- How do you finish a cut edge on Perspex?
- What protective equipment do you need?
- Frequently asked questions about cutting Perspex
- In short: cutting Perspex
Why is Perspex tricky to cut?
Perspex and Plexiglas are brand names for acrylic (PMMA). The material is hard and brittle. With teeth that are too coarse or too much pressure, you get hairline cracks or a corner snaps off. With a blunt blade or too much friction, the blade heats up and the acrylic melts, then welds itself back together behind the blade. What you are looking for is a pace at which the blade produces clean chips without getting hot.
Cast or extruded acrylic: does it matter?
Yes. There are two types of acrylic sheet:
- Cast acrylic (GS) is slightly harder and copes better with heat. It is easier to cut, drill and polish.
- Extruded acrylic (XT) is cheaper, but softens more quickly. It is therefore more likely to melt when the blade warms up.
If you do not know which type you have, check the protective film or ask your supplier. With extruded acrylic, cut a little more gently and keep the blade cool.
Which saw is best for Perspex?
The choice depends on the thickness of the sheet and the type of cut.
| Saw | Suitable for | Watch out for |
|---|---|---|
| Jigsaw | Curves, cut-outs, straight cuts in thin and medium sheets | Pendulum off, fine blade, support the sheet well |
| Circular saw | Long straight cuts, thicker sheets | Fine-toothed TCT blade, guide rail or batten |
| Coping saw or fretsaw | Small pieces and fine shapes | Slow, light pressure |
| Acrylic cutter (score and snap) | Thin sheets, straight lines | Only works on thin sheets |
For most jobs at home, a jigsaw is the most practical choice. A cordless jigsaw from the Maxxpack 18V range has no cable to get in the way, so you can move around the sheet easily. For long straight lengths, use a cordless circular saw with a suitable blade.
Which blade should you use for Perspex?
Choose a blade with fine teeth. For a jigsaw, blades for plastics or for non-ferrous metal (such as aluminium) are a good choice. They have small teeth with little set, which keeps the cut smooth. Coarse wood blades with large, set teeth are unsuitable: they snatch at the material and cause cracks.
For a circular saw, choose a TCT blade with a high tooth count, preferably one the manufacturer recommends for plastics or non-ferrous metal. Always use a sharp blade. A blunt blade heats up faster, and that is when the acrylic melts.
How should you set up your jigsaw for Perspex?
- Pendulum action off (setting 0). The pendulum action makes the saw faster in wood, but in acrylic it causes vibration, chipping and a rough edge.
- Medium speed. Start on a middle setting and make a test cut in an offcut. If the acrylic melts, turn the speed down or feed the saw a little faster. If you see small cracks or chips, turn the speed up slightly and reduce the pressure.
- Clean, smooth base plate. A scratch under the base plate means a scratch on your sheet. Leave the protective film on or put masking tape under the base plate.
With a circular saw, set the cutting depth so the blade only protrudes a few millimetres below the sheet. This reduces vibration.
How to cut Perspex in 6 steps
Mark out on the film
Leave the protective film on and draw your line on it. If there is no film, run masking tape along the cutting line.
Support the sheet
Lay the sheet flat on a sturdy workbench or on a sacrificial board. The part you are cutting off needs support too, otherwise it will snap off at the end of the cut.
Clamp it down
Secure the sheet with clamps. Put a piece of wood or card between the clamp and the sheet to avoid pressure marks.
Start off the sheet
Switch the saw on before the blade touches the material. Starting with the blade in the material increases the risk of a crack.
Cut at an even pace
Do not push hard. Let the blade do the work and keep a constant pace. With thick sheets, you can stop now and then to let the blade cool.
Remove the film last
Only peel off the film once you have finished. That way the sheet stays free of scratches while you finish the edges.
How do you stop Perspex melting or cracking?
These are the most common mistakes:
- Blunt or coarse blade. Use a new, fine blade.
- Pendulum action on. Always switch it off.
- Too much pressure. Pushing hard creates heat and stress in the sheet.
- Feeding too slowly at high speed. The blade then rubs more than it cuts, and the heat melts the plastic.
- A sheet that vibrates. Clamp closer to the cutting line and support both sides.
If it still melts, cut in short sections with pauses so the blade can cool down.
Can you cut Perspex without a saw?
You can score and snap thin sheets. Draw an acrylic cutter along a steel rule several times until there is a clear groove. Then place the groove on the edge of the table and press down on the overhanging part with one short, firm movement. This only works on thin sheets and straight lines.
For lots of identical pieces or complicated shapes, having the acrylic cut to size or laser cut by a supplier is often quicker.
How do you finish a cut edge on Perspex?
After cutting, the edge is matt and sometimes a little rough. This is how you get a neat edge:
- Deburr. Remove sharp edges with a fine file or a card scraper.
- Sand. Sand the edge with 240 grit paper, then 400 and, if you like, 600 to 800. Wet sanding produces less heat and fewer scratches.
- Polish. Use a polishing compound for plastics and a soft cloth, or a polishing pad at low speed. High speeds heat the edge up again.
Then clean the sheet with lukewarm water and a little washing-up liquid. Do not use glass cleaner containing alcohol or ammonia, as it causes hairline cracks in acrylic.
What protective equipment do you need?
Always wear safety glasses, because acrylic chips and splinters are sharp. Gloves help when handling the sheet, but do not wear them where they could get near the blade. If you are doing a lot of cutting, use hearing protection and a dust mask.
Frequently asked questions about cutting Perspex
Can I cut Perspex with an ordinary wood saw?
You can, but the result is rarely neat. A wood saw has large, set teeth that snatch at the material, so there is a high risk of cracks and broken corners. A fine-toothed saw for metal or plastics works much better.
What speed should I use for Perspex?
A medium speed is the starting point. The right speed depends on the thickness, the type of acrylic and your blade. Make a test cut in an offcut first and adjust: if it melts, go lower; if it cracks, go a little higher with less pressure.
How do I cut a round hole in Perspex?
First drill a hole inside the circle with a drill bit for plastics or a special acrylic bit. Insert the jigsaw blade into it and cut out the circle slowly. For smaller round holes, you can also use a hole saw at low speed.
Why is my cut in Perspex white and rough?
This is usually caused by a blunt blade, a speed that is too high or the pendulum action. The acrylic gets warm and melts slightly at the edge. With a sharp blade, the pendulum off and a little less pressure, the cut will be cleaner. Sand and polish the edge afterwards for a clear finish.
In short: cutting Perspex
Cut Perspex with a jigsaw and a fine blade for plastics or non-ferrous metal, at medium speed with the pendulum action off, or use a circular saw with a fine TCT blade for long straight cuts. Keep the film on, clamp and support the sheet, and cut at a steady pace without forcing it. Finish the edge by sanding and polishing for a clear result.
