CNC machined Polycarbonate

Polycarbonate sheet: Properties, cutting, and bending guide

Top 5 must-know things about polycarbonate

• Polycarbonate (PC) is a transparent thermoplastic known for its impact resistance and toughness. It’s up to 250x stronger than glass.
• At SendCutSend, polycarbonate is CNC routed for clean edges and precise details.
• We offer bending on polycarbonate, opening up more options for guards, covers, and enclosures.
• Parts can be tapped in-house for threaded holes.
• Available in multiple thicknesses, with parts shipping in 2–4 business days.

What is Polycarbonate?

Polycarbonate is an amorphous thermoplastic prized for its unique combination of toughness, optical clarity, and heat resistance. It is commonly used for safety glazing, machine guards, medical equipment, and protective enclosures. Unlike acrylic, which is stiffer but more brittle, polycarbonate can absorb impact without shattering. At SendCutSend, we machine polycarbonate sheets on CNC routers for precise, chip-free cuts, and now also offer bending and tapping services to expand how this versatile material can be used.

What are the core properties of polycarbonate?

Polycarbonate combines light weight and toughness in a way that few plastics can match. It’s about half the weight of glass while offering up to 250x more impact resistance.

• Clarity: Highly transparent, with light transmission around 88–90%.
• Strength: Outstanding impact resistance compared to acrylic or glass.
• Heat resistance: Continuous service up to ~250°F (121°C).
• Dimensional stability: Maintains toughness across a wide temperature range.
• Machinability: Easily cut, routed, or drilled, though it requires care to avoid edge melting.

These properties make polycarbonate an ideal choice for protective covers, shields, and enclosures where both visibility and durability matter.

Can polycarbonate be laser cut?

Polycarbonate does not respond well to laser cutting. The material tends to burn, discolor, or emit unpleasant fumes under a CO₂ laser. Instead, CNC routing is the preferred method. At SendCutSend, we cut polycarbonate exclusively on CNC routers, which deliver:

• Smooth, chip-free edges.
• Minimal heat buildup compared to laser cutting.
• Precise detail work without the risk of yellowing or toxic fumes.

What edge quality issues occur when cutting polycarbonate?

CNC routing produces crisp, accurate edges, but there are still a few considerations:

• Slight tool marks may be visible, especially on thicker sheets.
• Edge polishing is not offered in-house, so routed edges will have a machined, matte look rather than a glossy finish.
• Heat buildup is minimized, but improper feeds or tooling can cause melting in DIY setups.

In short, CNC routing is the cleanest, safest, and most precise method for cutting polycarbonate sheets.

What tolerances and minimum features are possible?

At SendCutSend, polycarbonate parts are cut to ±0.005″–0.010″, depending on thickness.

• Minimum hole size: ~0.125″ is recommended for best results.
• Minimum web/bridge width: At least 2x material thickness for structural integrity.
• Kerf width: Narrow, but depends on router bit size used.

For critical features like tapped holes or tight-fit assemblies, it’s best to consult our design guidelines before uploading your file.

Can polycarbonate be bent or formed?

Yes. Polycarbonate can be bent using two common methods:

• Cold bending: Thin sheets can be bent in a press brake without heating. This is the method used at SendCutSend. The material’s ductility allows sharp bends without cracking.
• Hot line bending: For thicker sheets or tight radii, localized heating can be applied before bending.

Compared to acrylic, polycarbonate bends far more reliably without cracking, making it a better choice for protective covers or enclosures.

What design rules should you follow for bending polycarbonate?

To ensure successful bends, keep in mind:

• Minimum inside bend radius: At least equal to material thickness; larger radii improve durability.
• Springback: Polycarbonate has noticeable springback, so press brake setups must account for this.
• Grain direction: Unlike metals, plastic sheets don’t have a rolling grain, so cracking is less of a concern.
• Post-bend clarity: Bend lines may appear slightly frosted, especially in clear polycarbonate.

For exact numbers and flange length requirements, see our bending guidelines.

Does polycarbonate scratch or yellow over time?

Yes, polycarbonate is more prone to scratching than glass. Over time, it can also yellow with prolonged UV exposure.

• Scratching: Can be minimized with protective films or hard coatings.
• Yellowing: UV-stabilized grades of polycarbonate perform better outdoors.
• Maintenance: Mild soap and water cleaning is recommended; avoid harsh solvents that may haze the surface.

For indoor machine guards, clarity lasts a long time. For outdoor or architectural uses, UV-protected grades are worth considering.

What are typical applications of polycarbonate?

Polycarbonate is widely used where toughness, clarity, and formability matter:

• Machine guards and safety shields
• Protective covers and housings
• Windows and panels for vehicles, boats, and equipment
• Light diffusers and optical lenses
• Enclosures and bent parts requiring impact resistance and transparency

When should you cut or bend polycarbonate yourself vs outsource?

DIY cutting of polycarbonate is possible with the right blades and routers, but it’s tricky:

• Tools can cause melted edges, chips, or cracks if feeds/speeds aren’t dialed in.
• Hand tools like jigsaws produce rough edges that often require sanding.
• Bending requires a press brake for crisp, repeatable bends—something most home shops don’t have.

Outsourcing to SendCutSend ensures:

• CNC-routed precision with ±0.005″–0.010″ tolerance.
• Professional bending with accurate angles and repeatability.
• Tapped holes and other services in the same workflow.
• Fast 2–4 day turnaround.

For prototypes or precision parts, outsourcing is usually faster and produces higher-quality results.

Can polycarbonate parts be tapped at SendCutSend?

Yes. Polycarbonate can be tapped to create threaded holes for fasteners, though design considerations apply:

• Thread strength: Polycarbonate threads are weaker than metal, so avoid over-tightening.
• Hole size and depth: Follow our tapping guidelines for supported diameters and depths.
• Applications: Great for enclosures, panels, and assemblies where lightweight, non-metal threads are acceptable.

This service saves time by delivering polycarbonate parts ready to assemble out of the box.

Conclusion

Polycarbonate is a tough, clear thermoplastic that bridges the gap between strength and optical clarity. While it doesn’t laser cut well, SendCutSend machines it on CNC routers for smooth edges and tight tolerances, with optional bending and tapping services to expand its use in protective covers, enclosures, and assemblies. Whether you need flat guards, bent housings, or threaded panels, SendCutSend delivers production-ready polycarbonate parts in just a few days.