The best way to make a hole in plastic depends on what you have available and what type of plastic you’re working with. A drill is the most reliable option for clean, precise holes, but you can also use a heated tool, a craft knife, or even a nail and hammer for softer materials. The main risk with any method is cracking the plastic or melting it unevenly, both of which are easy to avoid with the right technique.
Drilling: The Cleanest Option
A power drill gives you the most control over hole size and placement. Standard twist drill bits (the kind most people already own) work fine on soft plastics like polyethylene buckets, PVC pipe, and plastic storage bins. Keep the speed moderate and let the bit do the work without forcing it down.
Hard, brittle plastics like acrylic (Plexiglas) and polycarbonate (Lexan) are a different story. Standard bits tend to grab and crack these materials. Specialty plastic drill bits with a 60-degree or 90-degree point angle are designed to carve through the material instead of catching it. If you’re drilling into a clear plastic sheet, these are worth the few extra dollars.
Speed matters more than most people realize. For a 1/4-inch hole, aim for roughly 1,500 to 2,300 RPM. Smaller holes can handle higher speeds (up to 9,000 RPM for a 1/16-inch bit), while larger holes need slower speeds, down to about 800 to 1,200 RPM for a 1/2-inch bit. Too fast and friction melts the plastic around the hole, leaving a messy, uneven edge. If you see the plastic turning gummy or producing stringy shavings instead of small chips, slow down.
Preventing Cracks and Blowout
Thin plastic cracks most often right as the drill bit punches through the back side. The simplest fix is placing a scrap piece of wood underneath the plastic so the bit exits into wood instead of air. This supports the material from below and prevents the ugly splintering that ruins a project. Clamp both pieces together if you can, so nothing shifts mid-drill.
A few other things that help: mark your hole with a small indent (a thumbtack or center punch works) so the bit doesn’t wander across the surface. Start with a smaller pilot hole, then step up to your final size. And avoid pressing hard. Steady, gentle pressure lets the bit cut cleanly. Pushing too aggressively flexes the plastic and invites fractures, especially near edges.
Using Heat for Small Holes
When you need a small hole and don’t have a thin enough drill bit, a soldering iron works surprisingly well. The technique involves attaching a short piece of wire to the soldering iron’s tip, essentially creating a narrower heated point. Wrap the wire snugly around the tip so heat transfers efficiently, trim it to the shortest length you need, then let it heat up and press it through the plastic. The shorter the wire extension, the hotter it stays and the cleaner the hole.
A heated nail held with pliers is the low-tech version of the same idea. Heat the nail over a flame, then push it through. You’ll likely need to reheat it a couple of times for thicker material. The holes won’t be as precise as drilled ones, but for drainage holes in a planter or threading a wire through a project box, they’re perfectly adequate.
Fume Safety
Melting plastic releases gases you don’t want to breathe. PVC is the worst offender. Heating one kilogram of PVC to 300°C releases nearly 13 grams of hydrochloric acid gas and about 5 grams of carbon monoxide. You’re not melting a kilogram when making a hole, but even small amounts of HCl irritate your lungs and throat. Work near an open window or outdoors, and if you’re making more than a couple of holes, a fan blowing fumes away from your face makes a real difference. If you’re not sure what type of plastic you’re working with, treat it as PVC and ventilate accordingly.
No-Drill Methods That Work
For soft plastics like the lids of food containers, thin polyethylene sheets, or flexible packaging, you often don’t need power tools at all. A sharp craft knife or box cutter can punch through thin material if you twist it while pressing down. Place the plastic on a cutting mat or piece of cardboard so you don’t damage your work surface.
A leather punch or hole punch plier handles soft plastics up to a few millimeters thick and gives you a clean, round hole. These are especially useful for making evenly spaced holes in thin sheets, like for ventilation or lacing.
For slightly thicker material, you can drive a nail through with a hammer. Place a block of wood underneath, position the nail, and tap it through. The hole will be rough, so twist the nail as you pull it out to widen it slightly and clean up the edges.
Cleaning Up Rough Edges
Drilled holes often have a thin ridge of plastic (a burr) around the rim. A quick twist of a countersink bit removes it cleanly. If you don’t have one, a larger drill bit spun gently by hand over the hole opening shaves off the burr. For melted holes, a round needle file or a piece of rolled sandpaper smooths the inside walls. Folded sandpaper in 150 to 220 grit works well for most plastics without scratching the surrounding surface too badly.
If you need the hole to be a precise diameter, a tapered reamer lets you gradually widen it to the exact size. These are inexpensive hand tools that you twist into the hole, shaving off a little material with each rotation. They’re particularly useful when you’re fitting a bolt, grommet, or cable through the hole and need a snug fit.
Matching Method to Plastic Type
Soft, flexible plastics (polyethylene, polypropylene) are forgiving. They bend before they break, tolerate heat, and accept most drilling techniques without complaint. Polyethylene softens around 125°C and polypropylene around 160°C, so even moderate heat from a soldering iron pushes through them easily.
Hard, rigid plastics (acrylic, polycarbonate) crack if you rush. Use specialty bits, slow speeds, and always back the piece with wood. Acrylic is more brittle than polycarbonate, so it’s the one most likely to split if you use a standard bit or push too hard.
PVC pipe and fittings drill well with standard bits at moderate speed. The material is rigid enough to hold a clean hole but not so brittle that it shatters. Just keep it ventilated if you’re using heat, and let chips clear the flutes frequently by pulling the bit out partway every few seconds.