How to cut acrylic sheets to size

Perspex acrylic sheet has become very popular recently; particularly in the engineering, lighting, construction and manufacturing industries, so popular in-fact that it is now being used by hobbyists and DIY enthusiasts too! Cast acrylic is commonly used for glazing, signage and retail displays. Extruded acrylic is commonly used for lighting applications, interior decoration and screening. You may be wondering why acrylic is so widely used, and luckily the answer is very simple - its durability, versatility, flexibility and sustainability make acrylic the perfect, cheaper, alternative to glass and other plastics.

As long as you know how to cut it properly, acrylic is really easy to work with. Follow these simple steps and you will be able to achieve very good results.

Methods for cutting acrylic sheets

• Score and break
• Handsaw
• Jigsaw
• Bandsaw
• CNC Laser/Router cutting

How to score and break acrylic sheets

If your acrylic sheets are thin (no more than 5mm thick), then they can be cut using a sharp scoring tool - there's no need to use any power tools for sheets this thin.

You will require:

• Ruler/Set-square or long straight edge
• Marker pen or grease pencil
• Scoring knife
• Clamp (optional)
• Solid flat surface edge

Step 1: Draw your guideline

Firstly, determine where you want to cut the acrylic - simply mark this using a marker pen or grease pencil. With your ruler, draw a straight line along your chosen guidelines.

Step 2: Score along the guidelines

To ensure the panel doesn't move whilst scoring, clamp the material to a flat surface. Once in place, run your scoring knife along the marked line, using your ruler as a guide; by doing this, you will be cutting a narrow groove in the acrylic. Keep repeating this, ensuring you are cutting the acrylic deeper every time.

Step 3: Break off the scored edge

Place the scored line directly along a solid surface, facing up. The edge of a workbench or table work perfectly; just remember to use clamps to hold it in place. With a quick movement, push down on the overhanging edge to break it off. The groove will deepen as the acrylic sheet bends whilst the crack propagates through the sheet. Once done, you will be left with two pieces of acrylic perspex with fairly straight and clean edges!

If necessary, you can sand these edges, which we cover later in this article.

How to hand saw acrylic sheets

You will require:

• Hand saw with a fine-tooth blade (24/32 tooth blade preferable)
• Ruler/set-square or long straight edge
• Marker pen or grease pencil
• Clamp (optional)
• Solid flat surface edge

Step 1: Draw your guideline

First off, you need to create yourself a guide to follow when cutting. Just like scoring acrylic, mark the line you wish to cut along with a marker pen or grease pencil.

Step 2: Clamp your acrylic into place

Place your acrylic on a solid surface, hanging the part which needs sawing over the edge. To prevent the acrylic from moving, clamp it down to the solid surface. Avoid causing lots of movements or vibrations during the cutting process, as this is likely to result in acrylic chipping.

Step 3: Saw through the acrylic

Before you begin: please note that you should not use a saw designed for cutting wood. The teeth on the blades of woodworking saws are generally far too large which can shatter acrylic when cutting. Opt for a hacksaw with a fine tooth blade.

Start sawing along your line, ensuring that movement of the acrylic is kept to a minimum. Keep checking that you are sticking to the guideline; it can become very easy to go off-track whilst sawing. Once complete, there is a very high chance that there will be a rough edge, so it is worth sanding and polishing the acrylic perspex to restore its transparency and shine.

How to cut acrylic sheets with a jigsaw

You will require:

• Jigsaw (fine tooth blade required)
• Marker pen or grease pencil
• Clamp
• Solid flat surface/workbench
• Safety glasses

Step 1: Draw your acrylic

Jigsaws are one of the more favoured tools for cutting acrylic sheets. This is due to the fact that they produce a relatively clean cut and also allow you to create curved lines and shapes. So, as always, start with marking out the area you wish to cut with a marker pen or grease pencil.

Step 2: Clamp your acrylic in place

Similar to the method used with a handsaw, the process begins with clamping your acrylic down and ensuring there is no movement or vibrations which could result in the acrylic chipping.

Step 3: Saw through the acrylic and sand down

Important note: Jigsaws can be extremely dangerous; please read and follow the manufacturer's health and safety advice before using.

Using your jigsaw, cut along the line you made in step 1. Ensure you take some time to experiment with different cutting speeds, as this can have a huge impact on the quality of the cut. If you cut too slowly, the blade or acrylic can become too hot and melt; if you cut too fast, the desired pattern becomes harder to follow. Don’t worry - you can reduce these struggles by using non-flammable lubricants to reduce the heat.

How to cut acrylic sheets with a bandsaw

You will require:

• Bandsaw
• Marker pen or grease pencil
• Safety glasses

Step 1: Draw your guideline

Bandsaws are the perfect option for creating intricate and nonlinear shapes, due to being able to cut thick acrylic with perfect precision. To begin, like all cutting processes, use a permanent marker or grease pencil to mark the area you would like to cut.

Step 2: Select the right blade for cutting

Selecting the right blade for cutting is important especially if you are cutting curves into your acrylic. For best results, the number of teeth per inch on the blade should decrease as the thickness of the perspex increases. A general guide can be seen below:

Note: the values above are provided as a general guide; bear in mind that the thickness of the material also influences the choice of blade. Before making your final cuts, experiment with different blades.

Step 3: Set-up and start sawing

Before you begin: Bandsaws can be very dangerous when used inappropriately. Follow the manufacturer's health and safety guidelines for safe operation.

Once you have chosen the right blade width, you'll need to find the correct feed rate. The feed rate is the rate at which the material is fed through the cutting blade. The acrylic can melt or warp if the material is fed too quickly, so keep this in mind.

As you begin cutting the acrylic sheet, place down stiff-bristle brushes so they touch the tires which drive the blade. This helps to clear the build-up of acrylic swarf which risks the blade running off course if unmaintained. Continue to cut the acrylic to your desired shape - this may need sanding down afterwards.

CNC laser/router cutting perspex acrylic sheets

If you require complex or intricate designs cutting from materials such as acrylic, polycarbonate, ACM the most appropriate means is via a CNC Laser or Router (some materials are more suited to being cut on a router versus a laser). Using a CAD software package, the design is translated into a series of X/Y co-ordinates (otherwise known as a plot file) which the laser beam or router cutter follows to cut the required shape. The main difference between the two is that lasers cut with heat i.e. the laser beam whereas routers cut via sharp cutting toolbits.

Unlike traditional panel saws, both methods are capable of cutting shapes of all shapes and sizes to extremely tight tolerances, as small as 0.1mm is possible.

At Simply Plastics we operate two Tekcel CNC routers with a cutting area of 3m x 2m, and three CO2 lasers which are used on a daily basis to cut small intricate pieces used in a wide range of industries. Both types of machines are highly accurate and are capable of offering other finishing touches such as engraving, mitering and bevelling. If you require this type of accuracy on your project please get in touch - we are able to offer a bespoke cutting service for small quantities through to large batch runs of thousands of parts.

Drilling your acrylic

Never cut acrylic with cheap universal bits; acrylic can be a difficult material to work with, meaning complications can occur when not cut correctly. Typically, purpose made plastic cutting drill bits usually produce the best results, but good results can also be achieved when using a high-quality HSS drill bit.

To start, use a small drill bit to create pilot holes. From here, you can work up to your desired hole size. At all times, let the drill bit cut under its own weight - avoid forcing the drill bit into the acrylic sheet as this can cause the acrylic to crack, chip or break. In the unlikely case that the drill bit gets stuck in the acrylic sheet, simply put the drill into reverse to retrieve it.

A great tip is to spray a small amount of WD-40 onto your drill bit - this acts as a lubricant and helps to avoid the acrylic chipping or over-heating.

Sanding and polishing acrylic sheet

You will require:

• Metal file
• Sandpaper / Sanding Block
• Buffing wheel
• Drill

Step 1: File down rough edges

It’s important that your acrylic sheets have even edges. Use a metal file to smooth down any large chunks that may have been left behind whilst scoring or using a saw.

Step 2: Sand down the edges

Apply water to your sandpaper whilst it's on a sanding block. The sandpaper will need to be meticulously wet, so make sure you use enough water. From here, begin to sand down the edge. As the edge becomes ever smoother keep changing the sandpaper for a finer grit until you are left with 600-grit sandpaper.

Step 3: Buff the edges

Having used 600-grit sandpaper you should now have achieved a smooth finish, however to achieve a glossy and transparent finish you'll need to buff the edges of your perspex sheet. Attach your buffing wheel to an electric drill and apply a polishing compound either onto the buffing wheel or directly onto the acrylic. From here, you can simply buff down the edges until they have a shiny and smooth finish.