How to Cut Acrylic (Plexiglass) Sheet Without Cracking | Best Way to Cut Acrylic Sheet

2024.4.11

Cutting plexiglass sheets is often required when fabricating some custom parts and components for varying applications, such as manufacturing electronics housing and covers, how do you cut acrylic sheets without cracking? This guide will cover common plexiglass cutting methods, tools, and the best way to cut acrylic sheets of different thicknesses, even at home. 

Can You Cut Acrylic (Plexiglass) Sheets?

Yes, acrylic sheets, also known as plexiglass sheets, can be cut in various methods. Acrylic/plexiglass is a clear, break-resistant sheet form of poly(methyl methacrylate) or PMMA, this is a light-transmitting thermoplastic often used as a lightweight or shatter-resistant alternative to glass. It is possible to cut acrylic sheets, but the difficulty level and cost time are determined by lots of factors, such as material thickness and tools used. 

Best Ways to Cut Acrylic Sheet (Different Thickness) Without Cracking

If you do not have a laser cutter, how do you cut the acrylic sheet by hand? To avoid cracking during the process of cutting plexiglass sheets of different thicknesses (including extremely thin acrylic), here are the methods and steps. 

1)0.2-0.5mm acrylic sheets:

– To cut an acrylic sheet as thin as 0.2 to 0.5 mm, which is not much more than a paper, use a metal guide to ensure a straight line, and make sure it is fixed securely to prevent any movement during the cutting process. 

– Gentle and perfectly aligned strokes are necessary, which can create a clear path for the cutter to move without deviating from the desired line. 

– Carry out multiple soft strokes rather than applying too much force in a few strokes, to avoid the acrylic being cut too quickly, which could potentially lead to cracking. 

2)1-3mm acrylic sheets:

– Use a scoring knife with a flat hook blade, which can remove a small section of the acrylic board during each stroke, creating a groove. The depth of the groove should be about one-third of the thickness of the acrylic plate.

– During the cutting process, it is necessary to flip the acrylic board and make the same movement in the same position to form the same groove on the other side. The deeper the groove, the lower the risk of breakage during cutting, and the less likely the acrylic plate will rupture.

3)4mm+ acrylic sheets:

– When cutting such a thick acrylic board, it is best to use another cutting method and tool because it’s difficult to achieve the required depth without damaging the acrylic. It is recommended to use an angle grinder equipped with a metal cutting disc. 

– When cutting 4mm or thicker acrylic boards, to maintain the stability of the cutting line, two pieces of wood can be used to clamp the board as a guide for the grinder. 

– Be aware the cutting disc often becomes very hot due to the high speed of rotation of the mill, use it carefully.

 

Note:

– To avoid the formation of small pieces of melted acrylic, it is best to apply a short and gentle cutting method, so that the blade can cool down after each cut.

– Remove burrs or melted acrylic from the edges and polish them with sandpaper to obtain a smooth finish.

– Use a straight edge and go slowly for clean cuts on any thickness.

– Clamping securely is important for control of all thicknesses.

– If the cutting is offline, start the cutting again.

– Thicker acrylic may require cutting partway and then snapping off for straight breaks.

How to Cut Acrylic Sheet - Common Ways of Cutting Plexiglass Sheets

There are various methods to cut acrylic plexiglass sheets to choose from depending on your requirement and the thickness of the material.  

1. Laser Cutting: one of the most precise and clean methods for cutting acrylic sheets. It can produce intricate designs, sharp corners, and excellent edge quality. Laser cutting is particularly well-suited for thinner acrylic sheets, this method is ideal for projects requiring high accuracy and a professional finish.

2. CNC Routing: an excellent option for cutting acrylic sheets, especially for thicker materials. CNC routers can handle a wide range of acrylic thicknesses, from thin sheets to relatively thick blocks. It allows for the creation of complex shapes, profiles, and custom designs. CNC routing provides a high level of precision and can produce clean, smooth edges. For complex shapes, acrylic CNC machining allows sculpting details with a spindle-mounted endmill following CAD/CAM toolpaths.

3. Water Jet Cutting: a versatile method that can handle a wide range of acrylic thicknesses. It can produce highly intricate and complex cut patterns with excellent edge quality. Water jet cutting is particularly useful for thicker acrylic sheets, as it can cut cleanly without creating heat-affected zones or causing material distortion.

4. Scoring and Breaking: for simple, straight cuts on thinner acrylic sheets (typically up to 1/8 inch or 3 mm), scoring and breaking can be a cost-effective and easy method. This technique involves scoring a clean, continuous line on the acrylic and then snapping or breaking it along the scored line. While not as precise as other methods, this can be a good option for basic cuts.

 

How to cut a thin acrylic sheet without cracking? Here are some tips.

– Thin acrylic sheets are more susceptible to heat buildup and melting during cutting, especially with power tools like saws. This can cause the edges to become rough, jagged, or deformed. Techniques that minimize heat generation, like using a lower speed and sharper blades, are important.

– Maintaining a clean, smooth edge finish is more challenging with thin acrylic sheets. Techniques like scoring and snapping or using a dedicated acrylic cutting tool can help produce cleaner, straighter edges. Power tools like circular saws may leave a slightly rougher edge on thin acrylic.

– Securely clamping and supporting thin acrylic sheets is crucial to prevent vibration, shifting, or flexing during the cutting process. Using a sacrificial backer board or securing the acrylic to a stable work surface can help maintain accuracy and prevent chipping.

– Wear appropriate personal protective equipment, such as cut-resistant gloves, to avoid cuts and injuries. Ensure proper ventilation to minimize exposure to acrylic dust or fumes.

FacebookLinkedInPin