How to Drill Acrylic Sheet Without Cracking

Updated October 2026

Acrylic sheet drills cleanly when the bit cuts instead of grabs, the panel is fully supported and heat is carried away in chips. Cracks usually begin when a standard aggressive drill bit pulls into the sheet, the work flexes, or feed pressure is not reduced as the bit exits.

Use a purpose-made plastics drill or a correctly modified high-speed-steel bit. Test the setup on scrap of the same acrylic type and thickness before drilling the finished part.

Choose the bit

Point angle. Acrylic sheet manufacturers give a range of point angles, not one required angle. Plaskolite's OPTIX fabrication guide says drill point angles typically fall between 60° and 90°. ACRYLITE's drilling guidance gives the same 60°–90° range with a 0°–4° rake, so the bit scrapes instead of grabbing; it treats 90° as the general setting and notes 60° especially for holes 1/2 in and larger. Any angle in that range can drill clean holes if the bit is sharp, the sheet is backed and clamped, and feed is reduced at breakthrough.

In Go Industrial's fabrication shops, we prefer a 60° point with 0° rake, such as the Norseman Type 183-AG Chipfree™, for general shop work, hand-guided and drill-press drilling, and low- to medium-volume CNC runs. The narrower point enters the sheet gradually, which helps reduce chipping and grabbing at exit.

Whatever angle you use, follow your sheet manufacturer's guidance and test on scrap of the same type and thickness first.

A purpose-made plastic drill is the simplest choice. A conventional high-speed-steel bit can be modified by a competent fabricator, but inconsistent hand grinding can make the bit cut unevenly. Inspect it for chips and confirm both cutting lips are equal.

The Norseman Type 183-AG acrylic drill bit is available in seven diameters with selected multi-packs, plus a seven-piece set with a storage case. Compare sizes in the broader Acrylic Drill Bits collection.

Tools and materials

• Purpose-made acrylic/plastics drill bit or correctly modified HSS bit
• Drill press preferred for accuracy; controlled hand drill for suitable work
• Clean MDF, acrylic or thermoplastic backing board
• Clamps that secure the work without point loading
• Non-permanent marking method and protective masking
• Zero-flute countersink for deburring or countersinking
• Eye protection and chip-control equipment

Step-by-step method

1. Confirm the material

   Identify cast or extruded acrylic, thickness and any coating. Check the sheet supplier’s fabrication guidance because heat response and stress sensitivity can vary.

2. Lay out the hole

   Keep the factory masking in place and mark on the masking. Locate holes far enough from edges for the fastener and service conditions. Avoid centre punching acrylic with a metal punch.

3. Support the sheet

   Place the acrylic flat on a clean, continuous MDF, acrylic or thermoplastic backing board. Clamp both the panel and backing so neither can lift or vibrate. Keep clamps away from the drill path.

4. Set the bit and speed

   Install a sharp plastics bit square to the work. Select a moderate speed appropriate to diameter and thickness. The correct combination produces clean continuous chips without whitening, melting or violent grabbing.

5. Start with light feed

   Bring the bit into contact gently and establish the hole without forcing. Maintain a steady feed that lets the cutting edges remove material instead of rubbing.

6. Clear chips in deeper holes

   Use a peck-drilling action where needed: withdraw periodically so chips escape and heat does not build in the flute. Do not allow a wad of hot chips to polish or melt the hole wall.

7. Slow down at breakthrough

   Reduce feed pressure before the tip exits the underside. Let the backing support the acrylic while the full diameter passes through; this is where an aggressive bit most often grabs and chips the sheet.

8. Deburr carefully

   Use a zero-flute countersink or approved deburring method with very light pressure. Remove only the sharp edge unless the fastener design specifically requires a countersunk seat.

Large holes and fastening

For large diameters, use a tool and method approved for acrylic. A circle cutter should be used only in a drill press with the sheet and backing securely clamped—never freehand. Suitable hole saws need careful speed, chip clearing and backing.

Acrylic expands and contracts more than metal or glass. For point fastening, ACRYLITE’s guide recommends a drilled hole at least twice the bolt diameter and a hole centre at least 1.5 times the drilled-hole diameter from the sheet edge. Use appropriate washers and do not clamp the sheet rigidly; structural designs need project-specific engineering.

Common mistakes

• Using a sharp, aggressive general-purpose metal bit without modification
• Drilling an unsupported or flexing panel
• Holding the sheet by hand
• Forcing the bit or letting it rub until acrylic melts
• Failing to clear chips from a deep hole
• Maintaining full feed pressure at breakthrough
• Putting holes too close to an edge
• Tightening fasteners until the acrylic is rigidly clamped

Frequently asked questions

Can I use a normal drill bit?

A purpose-made plastics bit is safer and more predictable. A standard HSS bit can be reground to suitable geometry by someone who can keep both cutting lips equal. Test on matching scrap.

Why is the acrylic melting?

The bit may be rubbing, the speed may be too high for the setup, feed may be too light, or chips may be trapped. Stop, let the material cool and correct the cutting conditions.

Why did the underside chip?

The sheet may have lacked backing, the bit may have grabbed, or feed pressure stayed too high as it broke through. Support the underside and slow the feed before exit.

Should I countersink screw holes?

Only when the fastening design calls for it. Use a zero-flute countersink and remove material gently; over-countersinking can create stress concentrations.

Sources and further reading

• Plaskolite: OPTIX Fabrication Guide (Drilling)
• ACRYLITE: Drilling Fabrication Information
• GoIndustrial: Working with Acrylic Sheet

This guide provides general educational information. Products, substrates, site conditions and regulations vary. Follow the current technical data sheet, package directions and safety data sheet for every product you use. Code-regulated, structural or safety-critical work may require a qualified professional.