Drilling

Acrylic sheet drills cleanly with high-speed steel, modified-for-plastic twist drill bits. Unmodified metalworking drill bits will cause melting and other damage to the plastic. You can modify metalworking drill bits for plastic by grinding the tip angle to a sharp 60 to 90 degrees. The cutting edge must be ground "flat" to a 0- to4-degree rake angle, so it scrapes the acrylic rather than gouges it. A correctly shaped bit operated at the proper speed will create two continuous spiral strips as the bit passes evenly through the acrylic.

The work piece should be held firmly, preferably clamped to the worktable. Back the piece with acrylic or wood so the drill bit continues into solid material as it exits the bottom surface.

A circle cutter can be used for creating holes greater than 1 inch in diameter in acrylic sheet. Use a drill press with a cutting speed of about 400 rpm. Water or air to cool the cutter makes the hole walls smoother.