Drilling PLEXIGLAS®: Nine steps to the perfect drilled hole
PLEXIGLAS® is drilled as easily as wood a few special properties must be factored in, however. Find out which drill bits are suitable for PLEXIGLAS®, how to drill and what to look out for during the process. Before you start, prepare your workplace and lay out all necessary tools.
No time to spare? Here are some quick tips for readers in a hurry!
Do not remove masking film before drilling
Attach the PLEXIGLAS® sheet to a base
Use an appropriate drill bit, such as a specially ground twist bit
Determine the optimal rotational speed by drilling a test hole
A special drill, such as a bench drill or box column drill, is not a prerequisite for drilling PLEXIGLAS® sheets: Any commercially available drill is suitable. Rather than the drill itself, the right drill bit is decisively important for accurate results. One possibility, suitable for DIYers as well as experienced professionals, is a specially ground for acrylic drill bit. Depending on the cutting geometry, however, other drill bits may also be used. Find more details in the brochure titled Machining PLEXIGLAS®.
Spiral bit ground for PLEXIGLAS®
Special spiral drill bits are best suited for drilling PLEXIGLAS® sheets. These have a special cutting geometry: Their cutting edges are ground in such a way that the material is scraped rather than cut. This prevents cracking and breakouts.
Caption below image (max. 400 characters): Spade drill bits and Forstner drill bits, normally used for drilling wood, are also suitable for drilling acrylic sheets. When using bits of this kind, take care that the bits do not transport shavings out of the drill hole. To avoid this, remove shavings in regular intervals. Additionally, adequate cooling with water, for example, is necessary.
Conical drill bits are perfect for use with thin PLEXIGLAS® sheets and PLEXIGLAS® corrugated sheets and tubes. These result in slightly conical holes, which prevent chipping on the exit side of the hole.
For drilling holes of large diameter a hole saw with fine tooth pitch can be used with thin materials. A low rotational speed and adequate water cooling are important here. The spaces between the teeth of the hole saw should be cleaned regularly. For this type of drilling, the workpiece must be well secured.
For accurate drilling, first, lightly secure the sheet with clamps or screw clamps to a firm, level base, of wood, for example; this could be a workbench or table. Before each drilling session clean the base so that no sharp-edged parts project from it. You may also clamp the material in a bench vice with protective jaws. Align the workpiece accurately before clamping it.
The shavings produced while drilling indicate whether the rotational speed is correct. The images show the influence of rotational speed or cutting speed and feed rate on the quality of the drill hole, in this case with a PLEXIGLAS® sheet.
Place the drill bit on the marking indicated and drill briefly. In this way you can check the position of the borehole.
Switch on the drill before starting to drill.
Important: Shortly before drilling through the sheet, you should reduce the feed rate to prevent chipping.
Airing and cooling
For material thicknesses greater than 5 mm the drill bit should be regularly cooled down to prevent overheating. This is done by raising it briefly. You should also cool the drill hole. This is best done with water, which you fill into a wash bottle. Spray water into the hole at regular intervals. This is especially important for drill bits where shavings accumulate fast, such as when using spade drill bits.
Deburring the borehole
You should deburr the borehole on both sides, using a countersink; in this way the small notches arising during boring are prevented. For relatively large drill hole diameters you can use a scraper for deburring.