HOW TO DRILL POLYCARBONATE SHEETS CORRECTLY

Polycarbonate sheets are a popular material for roofing pergolas, terraces, carports and greenhouses. They are strong, impact-resistant and easy to machine. To achieve a clean hole without damaging the material, it is important to choose both the correct drill bit and the proper drilling technique. Polycarbonate sheets are generally divided into two categories: solid sheets and multiwall (hollow) sheets.

Lower Drilling Speeds Are Essential

The spindle speed should be set so that clean chips are produced. Otherwise, excessive heat may damage both the drill bit and the polycarbonate. Incorrect drilling conditions may also cause the material to crack.

We recommend drilling at a low speed and removing chips regularly. It is also advisable to use a backing board when the drill exits the material to prevent chipping or cracking around the exit hole.

How Large Should the Hole Be?

When drilling mounting holes in polycarbonate sheets, it is important to allow for the material's thermal expansion. The hole should generally be 2–3 mm larger than the diameter of the fixing fastener, allowing the sheet to expand and contract naturally with temperature changes without creating internal stress.

For multiwall polycarbonate sheets, holes should be drilled between the internal ribs while maintaining an adequate distance from the sheet edge.

Note: The exact size of mounting holes may vary depending on the type of polycarbonate sheet and the manufacturer's recommendations. Always follow the installation instructions supplied by the sheet manufacturer.

Which Drill Bits Are Best for Drilling Polycarbonate?

For clean and accurate holes, we recommend high-quality drill bits with sharp cutting edges:

• STEP-TIP HSS-G drill bits with a stepped point (DIN 338), Series 3621-ST
  The stepped point provides accurate positioning, reduces the tendency of the drill bit to "grab" the material and delivers exceptionally clean holes in both plastics and metals.
• Carbide hole cutters, Series 5420 (Ø 15–100 mm)
  Ideal for producing larger holes in solid polycarbonate sheets, for example for cable glands, ventilation openings or mounting components. Their carbide cutting edges produce clean hole edges, while low-speed drilling ensures accurate cutting without excessive heat build-up in the material.