Can Polycarbonate Be Drilled? Complete Fabrication Guide
Yes — polycarbonate sheets can be drilled, cut, routed, and shaped with standard tools. Here is exactly how to do it without cracking or melting your Lexan polycarbonate sheet.
January 2026 • 6 min read
The Short Answer
Yes, polycarbonate can absolutely be drilled. It machines very similarly to aluminium — it is tough, slightly elastic, and resists shattering. With the right technique and standard workshop tools you can drill clean, precise holes without cracking or melting the material.
Key Rules for Drilling Polycarbonate:
- Use a sharp HSS or brad-point drill bit
- Speed: 1,000–2,000 RPM (slow to medium)
- Light, steady pressure — let the bit do the work
- Do not let the bit dwell — keep it moving
- Support the sheet from underneath to prevent blowout
- Leave the protective film on while drilling
Best Drill Bits for Polycarbonate
Not all drill bits are equal for polycarbonate. The wrong bit causes cracking, melting, and rough edges.
HSS (High-Speed Steel) Bits — Best All-Round Choice
Standard HSS bits work well for most applications. Keep them sharp — a dull bit generates friction heat that melts the polycarbonate around the hole.
Brad-Point / Spur-Point Bits — Cleanest Results
The centre spur prevents the bit from wandering and the cutting spurs score the edge of the hole cleanly, reducing chipping. Recommended for finish work where hole appearance matters.
What to Avoid
- Spade bits: Crack sheets due to aggressive cutting action
- Self-centering bits: Generate too much heat at slow entry
- Dull bits of any type: Heat build-up causes melting and hazing around the hole
Step-by-Step: How to Drill Polycarbonate
Step 1 — Mark Your Hole
Mark the hole location with a marker directly on the protective film. Do not remove the film yet — it protects the surface and reduces vibration marks during drilling.
Step 2 — Support the Sheet
Place the sheet on a flat surface such as a scrap board. Clamp or hold it firmly so it cannot flex or vibrate while drilling. Unsupported sheets crack from vibration.
Step 3 — Set Your Speed
Set your drill to 1,000–2,000 RPM. Higher speeds generate heat; lower speeds can cause the bit to grab. For a cordless drill, medium speed with firm trigger pressure works well.
Step 4 — Drill Through
Apply steady, light pressure and keep the drill moving. Do not let the bit pause inside the hole. As you near the exit side, reduce pressure slightly to avoid blowout.
Step 5 — Deburr the Hole
A small amount of swarf (plastic shavings) will be produced. Remove them and lightly deburr the hole edge with a countersink bit or fine sandpaper if needed.
Important: Leave Room for Thermal Expansion
Polycarbonate expands and contracts significantly with temperature changes. When fastening sheets, drill holes 2–3mm larger than the fastener diameter to allow for this movement. Using tight-fit holes causes stress cracks around fasteners over time, especially on roofing and outdoor installations.
Thermal Expansion Rule of Thumb:
Polycarbonate expands approximately 0.065mm per metre per degree Celsius. A 3m sheet can move 5–8mm between a cold Canadian winter and a hot summer day. Always oversize your fixing holes.
Cutting Polycarbonate Sheets
Circular Saw
Use a fine-tooth carbide blade with 80+ teeth. Set the blade depth to just clear the sheet thickness. Feed slowly and steadily. Keep the protective film on.
Jigsaw
Use a fine-tooth blade (metal-cutting blade works well). Slow speed with orbital action set to zero. Support the sheet on both sides of the cut to prevent vibration cracking.
Scoring Knife (Thin Sheets Only)
For sheets up to 3mm, a sharp scoring knife and straight edge works. Score deeply 3–5 times, then snap the sheet over a straight edge.
Table Saw / Panel Saw
Ideal for straight cuts on larger sheets. Use a triple-chip or alternate-top-bevel carbide blade. Feed at a steady, moderate pace.
Routing Polycarbonate
A standard woodworking router with a straight or spiral carbide bit works very well for edge profiling, rebates, and decorative edges. Use a sharp bit, moderate feed rate, and take no more than 3mm depth per pass.
Common Mistakes to Avoid
- Removing the protective film too early: Keep it on until installation is complete
- Drilling too fast: Melts the material and creates ragged, fused hole edges
- No backing board: The sheet flexes on exit, cracking around the hole
- Tight fastener holes: Prevents thermal movement and causes stress cracking
- Using a hammer drill mode: Always drill in standard rotary mode — hammer action cracks polycarbonate
The Bottom Line
Drilling and cutting polycarbonate sheets is straightforward with the right approach. Sharp bits, moderate speeds, proper support, and oversized fixing holes are the keys to a clean, professional result. Whether you are installing a polycarbonate roof, greenhouse, or window replacement, these techniques will give you a clean finish every time.
Frequently Asked Questions
Can polycarbonate be drilled?
Yes. Polycarbonate can be drilled with standard HSS (high-speed steel) drill bits. Use slow to medium speeds (around 1,000–2,000 RPM), apply light pressure, and keep the bit cool. Avoid letting the bit dwell in one spot to prevent heat build-up and melting.
What drill bit is best for polycarbonate?
Standard HSS (high-speed steel) drill bits work well for polycarbonate. For cleaner holes, use a brad-point or spur-point bit. Carbide-tipped bits work too but are overkill for most applications. Avoid spade bits — they tend to crack the sheet.
How do you cut polycarbonate without cracking it?
Use a circular saw with a fine-tooth carbide blade (80+ teeth), a jigsaw with a fine-tooth blade, or a scoring knife for thin sheets. Always support the sheet fully, clamp it firmly, and cut slowly. Keep protective film on the sheet while cutting to reduce vibration marks.
Can you use a router on polycarbonate?
Yes. A standard woodworking router with a straight carbide bit works very well on polycarbonate for edge profiling and cutting. Use a moderate feed rate and keep the bit sharp to prevent melting.