Forstner Drill Bits:
Forstner drill bits have extra sharp cutting edges that drill smooth flat-bottomed holes in plastic. Forstner Drill Bits will fit 3/8" hand drills and drill presses.
Acrylic (or plastic) requires special tools for drilling, routing, sanding, and buffing. When drilling plastic, tighten the bit securely in the chuck. Support the plastic with soft wood, clamp, or hold the plastic firmly. Drilling small holes? Use highest speed available: up to 3000 rpm. If you are drilling holes 3/8"or larger, a slower drill speed (1000-2000 rpm) will improve the quality. Don't force feed the bit. Slow feed as the drill point penetrates the second surface. Always drill for a 1/16"oversize hole for plastic expansion. Drill the holes with at least 1/4"of solid material from the edge of the hole to the edge of the sheet. Use round-headed screws. Tighten the screws snugly and then back off with a 1/4" turn to allow movement for expansion or contraction of the plastic.