What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
What we cover
Why bit choice matters
Plastic and acrylic are easy to drill with a cordless drill, but they do not behave like wood. A wood bit can grab and pull itself into the sheet; a dull metal bit can rub, heat the material, and leave a melted edge. Acrylic is especially prone to cracking from heat, vibration, or pressure near an edge. The right bit helps, but a steady setup and light feed matter just as much.
For ordinary holes in thin plastic, a sharp twist bit is usually enough. For clean holes in acrylic sheet, a plastic-cutting bit with a shallower cutting angle is a safer choice. If you already own a sharp bit and only need a few holes in noncritical plastic, try it on scrap before buying anything.
As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
Choose a bit for the material
| Bit type | Best use | Trade-off |
|---|---|---|
| Plastic-cutting bit | Acrylic sheet and clean, repeatable holes | Costs more than a basic twist bit; less useful for general drilling |
| Sharp HSS twist bit | Thin, softer plastics and occasional holes | Standard point can grab or crack brittle acrylic |
| Brad-point bit | Some soft plastics where accurate starting matters | Spurs can catch; test first, especially on acrylic |
| Step bit | Enlarging holes in thin sheet and making larger round openings | Works best in thin material; can chatter or overheat if rushed |
| Hole saw | Large holes in sheet or plastic panels | More heat and vibration; needs careful support and a pilot hole |
A purpose-made plastic and acrylic drill bit set is worth considering if you regularly drill display panels, guards, or acrylic enclosures. These bits are ground to cut rather than aggressively pull into the work. For a one-off hole in a plastic storage bin, a sharp standard bit is often the better-value choice.
Set speed and pressure
Use a cordless drill in its low gear, if it has two gears, and keep the trigger controlled. There is no single ideal speed for every bit diameter and plastic thickness, but a practical starting range for small holes is about 500–1,000 rpm. Larger bits and hole saws generally need slower speeds. Check the bit maker’s guidance when available, and stop if the plastic begins to soften, smear, or smell hot.
Keep the bit moving through the material with light, steady pressure. Leaning hard on the drill can make the bit bite suddenly or push the sheet away from its support. Let the cutting edges do the work; if drilling becomes slow, the bit may be dull or the speed may be too high. A brief pause can let the area cool, but avoid repeatedly starting and stopping while the bit is trapped in the hole.
Hammer mode is for masonry, not plastic. Turn it off even if you are using a hammer drill. Impact drivers are also a poor fit for drilling acrylic: their hammering action can crack the sheet, and their trigger response is often less controlled for delicate work. Use a drill with a regular chuck instead.
Set up the work for a clean hole
Support the sheet flat on a sacrificial piece of plywood or a sturdy board. Clamp it without crushing it, and place the clamp close enough to limit vibration while keeping it clear of the bit. Do not hold a small piece in your hand while drilling. On acrylic, leave room around the hole: as a practical rule, keep the hole center at least 1.5 times the hole diameter from an edge, and farther away if the panel will be stressed by a fastener.
Mark the location with a removable marker or masking tape. A center punch can start a crack in acrylic, so do not strike one. Start slowly, keep the drill square to the sheet, and let the bit enter without forcing it. For a through-hole, reduce pressure as the tip approaches the back face. Backing material supports the exit side and reduces breakout.
For a hole larger than about 6 mm (1/4 inch), drilling a small pilot hole first can help keep a standard bit centered. With a step bit, use the pilot size recommended for that bit and stop at the step that matches the opening. A variable-speed cordless drill makes it easier to start gently and slow down for larger bits.
Avoid common failures
Cracks radiating from the hole: The sheet may be poorly supported, the bit may have grabbed, or the hole may be too close to an edge. Use a sharper or plastic-cutting bit, reduce feed pressure, and support both sides where possible.
Melted or ragged edges: The bit may be dull, spinning too fast, or rubbing instead of cutting. Stop and let the material cool. Clean melted plastic from the bit before continuing; a clogged cutting edge creates more heat. Do not use a flame to smooth the edge, since heat can cause warping or damage.
Bit wandering at the start: A curved or smooth sheet can let the bit skate. Tape can help mark the spot, but it does not replace clamping. Start at low speed and use a guide block with a hole if precise placement matters.
Remove burrs with a fine file or scraper, using light strokes. For acrylic, avoid twisting a knife hard against the hole edge. If the fastener needs clearance, drill the opening slightly larger than the screw shank rather than forcing a screw through a tight hole. Tight screws and overtightened washers can split acrylic even after a clean drill job.
What to buy for your job
For occasional holes in soft plastic, a good-quality sharp HSS twist bit is fine; there is little reason to buy a specialized set for one small repair. For repeated work in acrylic, choose plastic-cutting bits in the sizes you use most, rather than a large assortment of unknown quality. If you need wide holes in thin panels, a step bit is convenient, but use low speed and stop if the sheet starts to chatter.
For openings larger than a step bit handles neatly, a fine-tooth hole saw suited to plastic can work, provided the panel is firmly supported. Hole saws remove more material and generate more heat, so they are not the best choice for a thin, fragile acrylic panel unless you can clamp it flat and drill slowly. When the hole must be especially clean or the panel is expensive, test the complete setup on offcuts first.