Polycarbonate vs acrylic: which clear plastic?
Polycarbonate (Lexan) vs acrylic (plexiglass): impact strength, clarity, scratch resistance, machining, cost, and when to choose each for clear parts.
Acrylic (plexiglass, PMMA) is harder, clearer, cheaper and easier to polish, but it cracks. Polycarbonate (Lexan, PC) is nearly unbreakable and takes heat and machining abuse, but it scratches easily and costs more. If the part can shatter and hurt someone, or it gets bolted, bent or impacted, use polycarbonate. If it is a clear window, display or lens where optical clarity and scratch resistance matter and it will not take a hit, use acrylic.
The core trade-off
Both are clear thermoplastics, but they fail in opposite ways: acrylic is rigid and scratch-resistant but brittle, polycarbonate is tough and impact-proof but soft on the surface.
| Property | Acrylic (PMMA / plexiglass) | Polycarbonate (PC / Lexan) |
|---|---|---|
| Impact strength | Low (cracks) | Very high (near unbreakable) |
| Optical clarity | Excellent, stays clear | Very good, can yellow over years |
| Scratch resistance | Good | Poor (needs hard coat) |
| Machinability | Machines and polishes clean, can chip | Machines easily, does not crack |
| Heat / temperature | Lower | Higher, more heat-resistant |
| Cost | Lower | Higher |
| Best for | Windows, displays, lenses, signage | Guards, glazing, enclosures, impact parts |
When to choose polycarbonate
Machine guards, safety glazing, equipment enclosures, and anything that gets drilled, tapped, cold-formed or impacted. Acrylic will craze and crack around a bolt hole or a bend; polycarbonate shrugs it off. It is the default for robotics and automation guarding and anywhere a person could be hurt by a shatter.
When to choose acrylic
Clear windows, retail displays, light pipes and lenses, and signage where you want the best clarity, a scratch-resistant surface and the lower price, and the part will not take an impact. Acrylic also flame-polishes to a glass-like edge, which polycarbonate does not do as well.
Machining both
Both machine on the same CNC equipment as metals but want sharp tooling, high speeds and low feed to avoid melting and chipping. Polycarbonate is forgiving and does not crack; acrylic is more prone to chipping and crazing, especially around holes, so it wants sharp tools and sometimes annealing to relieve stress. Neither likes aggressive coolant chemistries. For a scratch-prone polycarbonate part, specify a hard coat.
What to send for a quote
The part, whether it needs impact resistance or optical clarity (that one answer usually picks the material), thickness, any hole or bend features, and whether you need a hard coat or a polished edge. Request quotes from Canadian shops that machine plastics, or that injection mould them at volume.
FAQ
What is the difference between polycarbonate and acrylic?
Polycarbonate (Lexan) is tough and nearly unbreakable but scratches easily; acrylic (plexiglass) is clearer, harder on the surface and cheaper, but it is brittle and cracks.
Is Lexan the same as polycarbonate? Is plexiglass the same as acrylic?
Yes. Lexan is a brand name for polycarbonate, and plexiglass (and Perspex) are brand names for acrylic (PMMA).
Which is stronger, acrylic or polycarbonate?
Polycarbonate, by far, in impact. It is used for bullet-resistant glazing and machine guards. Acrylic is more rigid and scratch-resistant but shatters under impact.
Which is better for machining?
Polycarbonate is more forgiving because it does not crack when drilled, tapped or bent. Acrylic machines to a cleaner, more polishable finish but can chip and craze, so it needs sharp tooling.
Which is cheaper?
Acrylic is generally cheaper than polycarbonate, which is one reason it is used for displays and signage where impact strength is not required.
Last reviewed: October 2026. Related reading: what is CNC machining and injection molding cost.
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